That's how Genma and Raido, reassured that she could defend herself, continued practicing with her whenever they had free time. Naruto and Sasuke, who had missions, trained with their teachers when they could, but a clear difference between them was beginning to show. While she spent practically all day training, they had missions and couldn't afford to practice and learn new jutsus while working. As expected.
When they were home, she let them practice with her clones so they could close the gap again. The only result was that they all ended up exhausted from training, as it was all they did in their spare time.
"Have you already read everything I gave you?" Tsunade-sama raised an eyebrow. "You finished faster than I expected."
"With the help of my clones, it was much easier."
"I imagine so... Alright. I'll give you an extensive exam. I hope you're prepared."
The exam was a written test with a practical and oral part. She spent the entire day answering the Hokage's questions. When she finished, the relief of finally accomplishing one of her goals was immense.
"I'll let Shizune grade it," she said, gesturing to the more than 50 pages of questions, "but if you answered as well as you did in the other part of the exam, there won't be much to correct."
While waiting for the Hokage's assistant's response, she dedicated herself to solving strange cases at the hospital. The truth was that with her diagnostic spell, they were hardly 'strange' since she knew exactly what was wrong with the patient, but treating them was a different matter. Isaribi, the girl they captured during the mission in the Sea Country, was one of those cases. Tsunade-sama, instead of helping her, gave her the file with her initial notes and left her to figure it out.
"Consider this a test!" she had said as she walked back to her office, turning her back.
She left her there with her former enemy, as if it was nothing. Seina rolled her eyes while reading Isaribi's medical history. Meanwhile, Isaribi watched her nervously, not knowing what to think until she asked her to calm down.
"I won't do anything to you," she assured. "You were my mission, that's all."
"I know... I'm very sorry for everything that happened. I felt trapped," she confessed. "I couldn't stand my appearance and the villagers' hatred any longer, especially when I was the reason they were so afraid."
"I know, that's why I captured you," Seina sighed. "We thought that if we brought you to Konoha, it would prove your innocence and you could be treated here. It's fate, or Tsunade-sama, that gave me your case."
"So, you're a medical ninja?"
"Yes. I hope I can help you," she nodded. "Let's see. First, I have a question.'"
"Go ahead."
"What do you want to achieve from the treatment? Do you want to fully recover your human body, or would you prefer to regain your human appearance while keeping your new abilities?"
"I don't see how the second option would be possible. I hadn't even considered it."
"Oh, I assure you it is possible" she laughed. "In fact, off the top of my head, I'd say it's easier than reverting you to a human. Your DNA has been transformed, not just your appearance. That means to 'cure' you, we would need to modify your DNA again."
"And how would you manage to keep my abilities but return me to my normal appearance?"
"I can think of several ways. I'd have to think about how to do it, but I need to know which option you lean towards first. Before you decide, I just want to assure you that both are possible."
"Thank you."
"I'll give you a couple of days to think about it, okay? Meanwhile, I'll do the same. Still, I need to examine both of your forms to see what I need to do."
She assessed Isaribi in her human form and her transformed form. Returning her human appearance in her human form would be ridiculously easy. She would only need to tattoo a few runes so that she never had to worry about it again. The problem was how to maintain her human appearance, or an aesthetically pleasing change, while she was transformed. The simplest option would be to implant a metal piece under the skin with runes that would physically alter her appearance. She could do the same with a bracelet or an earring, but this way, Isaribi would never have to worry about losing or destroying the one thing that kept her looking "human." She left the hospital with all the necessary information.
In her spare time, knowing she had given a two-day deadline, she created a rune sequence on a flat, rounded piece of titanium to give her human skin, human teeth, reduce the musculature in her limbs, and suppress the fins. Basically, her swimming abilities would be greatly reduced as she would only have webbed fingers and gills on either side of her neck. In return, she would have a normal appearance with the only exceptions being the webs and the gills. Easy and simple. Although she couldn't even take credit. Ancient egyptian wizards and witches had been using this sequence, in reverse, to change their human heads to animal heads for centuries, making muggles believe they were gods.
If she wanted to completely get rid of her transformation, she would have to put her to sleep and use a cellular manipulation jutsu to purge the foreign DNA from her cells. It would be a slow and tedious process, although she might be able to speed it up with a genjutsu to manipulate Isaribi's brain. The problem was that she didn't know if it would work and/or if it would kill her due to the acceleration.
Either way, when her next appointment came, she had options for both cases. If Seina were Isaribi, she would have kept her enhanced ability to swim and dive. However, Isaribi had been a victim of Orochimaru and Amachi for 10 years, so she would probably prefer to forget everything, even if it meant losing an advantage at sea. She entered the hospital mentally noting what she needed to take to operate on her. Nothing prepared her for her patient's decision.
"I want to keep my abilities. They have ruined my life for many years, but… if now I can be normal while being able to breathe underwater… I'll be the one to gain something, after all."
"Wow. You've surprised me" she admitted. "I thought you'd prefer to forget everything."
"I thought so too. Until this morning, that was my decision, but then I realized that the ability itself is not a bad thing. My problem is how they experimented on me without my consent, how they forced me to do their dirty work, how they took away my confidence to the point where I didn't defend myself from my neighbors' attacks. I just… existed."
"I understand" Seina nodded. "I'm glad you made this decision. I have everything ready. For either option."
"Now?" Isaribi asked, surprised.
"Yes. I just have to anesthetize your nape. I'll make a small incision in your neck and place a titanium talisman with fuinjutsu."
She asked for a drop of blood in her transformed state, which was when the foreign DNA activated, and proceeded with the operation. It only took 10 minutes to anesthetize her locally, sterilize everything, place the implant under her skin, activate the runes, and heal the wound.
"Let's see if it works. How do you feel?"
"I feel a tingling all over my body, but it's disappearing."
"Great. We'll wait for it to stop, and then you should transform."
About 5 minutes later, Isaribi stood up to try transforming. She managed to transform but kept her body intact. As soon as she saw her hands and arms, she started crying. She hoped it was out of happiness.
"How is it possible?" she wondered. "I never would have imagined that—"
She burst into tears, throwing herself into a hug, and then examined herself in a mirror that had been specially prepared for this. She touched her face, hair, and examined her teeth until she slowly realized it was real. She transformed back into her human form at Seina's request and saw that she had regained her original appearance.
"I can go home" she cried with a radiant smile. "I'm not a monster anymore."
Seina consoled her for a while until she could no longer stay with her. She examined her one last time before letting her go, and filled out the report before she got lazy. Luckily, no one seemed to have noticed Isaribi's recovery, so she left before they could bombard her with medical questions.
When she got home, her whole team was waiting for her, to her great surprise.
"You're all here! What a surprise!"
"We just ran into each other at the village entrance," Sasuke told her.
"Were you at the hospital, nee-chan?" Naruto asked as if he didn't know her schedule by heart.
"Yes. In fact, I was treating Isaribi."
"The experiment girl from your mission in the Land of the Sea?"
"The same. She decided to keep her new abilities, but only if she could have her human appearance back," she shrugged. "And you guys? What have you been up to? Anything interesting?"
"No. Just a moving job where some bandits showed up later," Sasuke sighed. "Could have been more interesting."
"Mine was more interesting! Our client, Princess Fukku, hired Ino and me to secure her a date with the man she was in love with."
"And why is that?"
"Apparently, she wanted to introduce herself personally, but she was so nervous that she gained like 20 kilos, so Ino, who looked just like her when she was slim, had to impersonate her to win over the guy."
Kakashi-sensei, Sasuke, and she chuckled at the ridiculous reason they had hired a couple of ninjas.
"And what happened in the end?" Kakashi-sensei asked. "Knowing you were hired, I know it wasn't that easy."
"Eh, hehehe" Naruto scratched his head with a blush on his cheeks.
"Oh, I'm not missing this. Let me see what happened, Naru" she asked with a smile.
Sasuke and Seina watched as Naruto recapped everything that happened. From Princess Fukku's explanation, Ino's disappointment when she realized the suitor was as fat as the princess, his pathetic way of seducing Ino… The best part came when Naruto started to get impatient because Ino wasn't very convinced to keep seducing the suitor. Sasuke and she saw how he transformed with a henge and how he felt the urge to pee. Instead of going to the bathroom or transforming back to his original self, he started peeing right in the garden, to the anger of their client.
Seina couldn't breathe from laughing as she watched him run with his pants down and his hands covering his parts, probably holding his penis while peeing as he ran. Sasuke, beside her, was crying with laughter. The best part came moments later. Ino opened the paper door to the inner courtyard and raised her hand with a delighted expression, looking at the rainbow and thinking it was raining. It took her a couple of seconds to realize it was Naruto's pee she was touching with her hand.
"Is it that funny?" Kakashi-sensei asked curiously, seeing Sasuke and her, by that point, unable to speak or breathe.
She motioned for him to come closer, crying, and touched his forehead with a magic-filled finger while implanting the memory in his mind. She watched through tears as Kakashi-sensei saw Naruto's memory. She saw his shoulders shake, trying not to laugh out loud.
"Wait, I have another memory to show you" she cleared her throat, remembering Genma.
She gave him a copy of her memory. Even though he tried not to laugh out loud at his fellow jonin, he couldn't help but double over with laughter when he saw Genma tap dancing and Raido cracking up. Sasuke and Naruto, who had seen what she was transferring, started laughing again.
"God… My ribs hurt" she admitted minutes later, when she caught her breath.
"You've given me a lot of material" the jonin smiled broadly. "I've never seen that expression on Genma's face, and he's always the one making jokes and teasing people."
"Did you make dinner?" she asked.
"We didn't have time to start."
"No problem. I'll leave a few clones cooking."
"I see you no longer have your clones studying textbooks," the jonin noted. "Have you finished studying?"
"At least until I have to study for the jonin exams" she groaned.
"Take a break until then. You have 2 weeks until you get promoted."
"I can't believe they're going to promote you, nee-chan!" Naruto smiled. "That's awesome!"
"The best part is that we also learn at the same time" Sasuke said, setting the glasses and plates. "Besides, Naruto and I can go directly from chunin to jonin."
"That's if they promote you next June."
"Where will the exams be next year?" Naruto asked.
"In Sunagakure" the jonin smiled. "You've been very lucky considering the exam location is decided by lottery."
"What do you mean we've been lucky?"
"Some villages are better avoided for sending Konoha's genins for the exam... For this team, all villages except Sunagakure pose a real danger. Still, you'll be accompanied by your jonin sensei, so there won't be any problem."
"Does that mean I won't be able to go?" she asked, frowning.
"Hm… I don't think so. Although we could ask Tsunade-sama. If it had been Kumogakure, I would have given you a resounding no. Kumo not only tried to kidnap your companion Hinata, betraying a newly signed peace treaty, but also tried the same with your mother."
"Really?"
"That's right. For this team to go to Kumogakure would be dangerous. Sasuke because of his dojutsu and Naruto because of who his father is... But it would also be dangerous to go to Kiri because of the sharingan and Yagura's purge, and also to Iwagakure due to the defeats they suffered at the hands of the Fourth and also because of me."
"Damn, we can't go anywhere with you," Naruto complained, half-joking, half-serious.
Seina stifled a laugh. Sasuke gave his brother a whack on the head, rolling his eyes.
"The truth is, we have many enemies. All villages have them, to be honest. Our firmest alliance is with Sunagakure. The other villages don't even have that."
They talked about the chunin exams a while longer. The biggest question was who would temporarily take their place so their team could participate in the exam. She supposed team 10 had the same problem. Anyway, they wouldn't have to worry about it for another 7 months.
The last weeks of training were the hardest. Not only was she at the hospital every morning and training half the afternoons with the Hokage, but she also had to practice in her spare time to meet her ninjutsu goals and finish her team's gifts. Due to the lack of time, she decided not to complicate her life thinking and took the quick route. She grabbed the ninja tents and started her magical project. Since she had done the same process with the suitcase she used for her summons, building a magical tent with an interior that was a gigantic house was much easier and quicker.
To her different jonin teachers, who helped her practice every week, and to Shizune and Tsunade-sama, as well as to Katsuyu, she also gave some gifts. To the jonin, she made different types of bottomless backpacks, while to Shizune, she gave an infinite pages diary, knowing how much she liked to write about anything and how much she hated losing papers or disorder. To Tsunade-sama, she gave a bracelet with a henge written in runes. Treating Isaribi had given her the idea, and she knew that the Hokage, since she had confessed it herself, constantly used the transformation jutsu to look younger. That way, with the bracelet, she could stop consuming chakra and not worry about her appearance. The hardest one had been Katsuyu. What do you give to a 460-meter-tall talking slug? She ended up giving her a "voucher" for the use of another spell she wanted.
"How did you do it?" Shizune asked her, delighted, days later. "No matter how hard I try to reach the end, I never run out of pages!"
"It's very easy. A jutsu to duplicate the blank pages each time one is filled, and another to increase the dimension of the diary inside."
"Easy," the Hokage chuckled. "Maybe for you. Come. I have to teach you my latest medical jutsu."
She followed the Hokage to an empty room in the hospital. She enchanted the place so no one could spy on them and nodded.
"What I'm going to teach you now is my ultimate trump card. The definitive iryo ninjutsu that a person can use on themselves at the brink of certain death. This jutsu is called sozo saisei or creation rebirth. Do you see this seal on my forehead?" she pointed to the small violet diamond. "That seal is called 'strength of a hundred.' When I'm mortally wounded in battle, I release this seal, causing total instant mitosis. That means I can regenerate instantly, effectively making me immortal."
Seina looked at her in amazement. She observed the small seal that she had previously overlooked, thinking it was a tattoo.
"The problem with this is that, if used to regenerate major injuries, it shortens the user's life due to the limited number of mitotic divisions in the human body. If you use it to regenerate an organ, it won't have the same impact as if you use it, for example, at the brink of death after being completely crushed by a rock. Likewise, you don't necessarily have to use this jutsu to regenerate your body; you can use your stored chakra as an extra chakra reserve for fighting."
She explained the necessary seals to start the forehead seal and also to release it. She informed her that until a prolonged period passed constantly gathering a certain amount of chakra, it wouldn't be fully completed.
"Will the time needed to complete the seal be the same for me as it is for you?"
"The seal has a finite limit, meaning that although it can store an infinite amount of chakra, it can only constantly accept a finite amount of energy. So, even with your enormous reserves, you can't flood the seal hoping to fill it in a minute. That's one of the drawbacks."
"I see."
"It takes me exactly 2 years to fill the seal each time, and only if I give it the maximum chakra constantly every day of the year. If at any point I stopped, for any reason, storing chakra, it would take a bit longer to fill it."
"And what would happen if I filled it with my chakra and Kurama's?" she asked with scientific interest.
"...I don't know. Still, I wouldn't try it. This is primarily a medical jutsu, and Kurama's chakra, like that of other bijuus, is corrosive if not properly molded."
"Alright. When can I start?" Seina asked, excited by the new challenge.
"Now."
She handed her a mirror so she could place the seal in the middle of her forehead. It wasn't visible yet, but she felt its presence on her skin. She immediately felt a sort of... void originating from the seal, as if it were thirsty. She manipulated a thread of chakra to her forehead, starting to fill it. She quickly noticed that Tsunade-sama was right about the "input limit." Using more chakra would be like trying to push a melon through a keyhole. Physically impossible. She metaphorically tied that thread of chakra to the seal with her mental barriers and disengaged from it.
"Well done," Tsunade-sama said, touching her forehead. "I can feel your chakra storing. If you don't falter a single day, in 2 years, this diamond-shaped seal will appear on your forehead. Then you'll know it's complete."
"In 2 years... I can hardly imagine it," she thought aloud.
"Time flies. You'll see. It will pass even faster when you return to active duty in a week," Tsunade-sama assured her with a smile. "You've held up well all this time. I'm proud."
"Huh. Sometimes I could hardly distinguish one day from another," she said wryly, "and I've gone up to 10 days without seeing my team. It was strange."
"I'm not surprised. Not only have you spent more than 8 months working with them constantly, but, as far as I know, you also live with them," she shook her head. "I couldn't have lived with Orochimaru and Jiraiya in the same place. We would have killed each other."
Seina laughed, imagining the punches the pervert would have received if he lived with Tsunade-sama. Even so, if they had lived together, maybe Orochimaru would have taken a different path... They would never know.