Here's a polished version of your passage with grammar improved, flow smoothed, and narration kept intact without changing your words or tone too much:
After training the trio, Hiko returned to the company, parked his car, and stood under the Strawberry Production Co., Ltd. sign, pulling out his phone to play Tetris while he waited.
Before starting, he glanced at the time, estimating when they would return.
But as the estimated time passed, the five girls still hadn't shown up.
'Strange. They've been gone so long. Nothing could have happened to them… right?'
Putting his phone away, Hiko paced around the company entrance, growing a bit anxious. He kept looking into the distance, but still saw no sign of them. Just as he was about to head out and look, he finally spotted the five girls running back.
"You're more than ten minutes later than I expected," Hiko said sternly.
In truth, they were only three minutes behind his estimate.
"We're girls. You can't expect us to have the same stamina as boys."
Ai stepped forward as their leader to negotiate. "Besides, we're really tired right now."
"Poor stamina? Then you should train even harder! From now on, you'll have at least two physical training sessions a day!" Hiko declared without mercy, even when Ai herself spoke up.
Arisa, who had gone home the night before to research and prepare, immediately countered:
"Your training plan is unreasonable. We just spent nearly an hour running the route you set. If we do that twice a day, that's 120 minutes. The recommended time for daily exercise is only 40–60 minutes."
"That's the standard for ordinary people, not for idols."
Hiko, who had prepared for this, continued, "Being an idol isn't easy. And by 'physical training,' I don't mean just running two long routes."
Then, looking at Arisa, who still seemed energetic, he said, "You seem to have plenty of energy. I gave you the dance step diagrams last night, so you must've mastered them by now. Come on, show me."
"I'll dance when we get back to the practice room!" Arisa shot back confidently. She had practiced many times at home last night and was ready for his challenge.
"What are you thinking? You want to be an idol, yet you're afraid of performing on the street?" Hiko provoked her.
"I'll dance!"
Though embarrassed at first, Arisa was baited into it. She was about to start when Ai quickly held her back.
"Saito-san, please don't make her perform here. Let's go back to the practice room."
Ai sensed something was wrong. Though she'd been annoyed with Arisa's attitude yesterday, she had a strong premonition that dancing in public would ruin her idol career. That's why she stopped her.
Hiko, whose anger had been rising at Arisa's defiance and who had wanted to embarrass her, calmed slightly at Ai's words. He nodded. "Since your leader has spoken, I'll make some exceptions and won't make you perform on the street."
"Who cares about your fake concern! I'm not afraid of performing here!…" Arisa snapped, but Ai tugged at her sleeve, making it hard for her to keep going. With no choice, she muttered, "Since the leader says to do it inside, I'll listen to her."
Hiko abandoned his original plan to push further and led them inside.
The six entered the dance practice room.
"Begin your performance," Hiko said flatly.
"Hmph! Don't be too surprised!"
Arisa walked to the front and performed the movements she had memorized from the diagram, one pose after another.
When she finished, she lifted her chin like a proud swan. "Well? Weren't you amazed?"
"What nonsense are you dancing?! I drew out the steps clearly for you. Not only did you perform poorly, you even changed the moves on your own! And not just changed them, but changed them terribly!"
Hiko's face was stern.
The diagrams were accurate, but without long-term practice, no one could execute them perfectly on the first try. Originally, Hiko hadn't planned to make a fuss, but Arisa had walked right into it.
"You're talking nonsense! How could I have danced wrong? You're just slandering me!" Arisa protested.
"Not only are you foolish, you're arrogant too. You don't even have the humility to accept training. I think you should just pack your bags and leave."
Knowing Arisa wouldn't admit fault so easily, Hiko pressed on. "All of you, watch her movements a few times! Then I'll show you what true standards are."
He made them study the diagrams for over ten minutes before speaking again.
"Open your eyes and watch. The movements in the diagrams are like this. Pay attention!"
With a stack of cards in hand, Hiko recreated the exact dance steps the system had given him—without the slightest deviation.
Ai fell silent.
Arisa also fell silent.
The other three said nothing.
Earlier, when they'd only looked at the diagrams, they had thought Arisa's performance was correct. But after watching Hiko's demonstration, the flaws were undeniable, her arm angles were wrong, her steps were too short or too wide.
"Now you have nothing to say, do you? You arrogant fool!" Hiko barked.
"You're deliberately making things hard for me…" Arisa knew she was wrong but still clung to excuses.
"That's absurd. I gave the same diagrams to everyone yesterday. Where's that bold attitude you had earlier? You turn around and say I'm picking on you? Why not just accuse the diagrams of being wrong? You only complain that I'm targeting you?"
"How could I memorize and perfectly perform all the steps in one night… You're just targeting me…" Arisa's voice cracked as tears welled up.
"Cry, cry, cry! All you ever do is cry. Not only arrogant and foolish, but thin-skinned too. The moment things don't go your way, you whine that I'm targeting you. Pathetic. I have no reason to target you…"
Hiko was about to add "I could have the President replace you anytime" when Watanabe cut in:
"Don't argue anymore. This will only make things worse. Saito-san, please try to understand her…"
"Understand her? Has she ever understood me? She's caused trouble again and again—arrogant, defiant. And you're still pleading for her?" Hiko snapped mercilessly. "I thought your personality was decent, but siding with her like this only makes you seem pretentious."
"If all of you are going to be like this, then I'll just have the President replace you all!"
---
I'm kinda sick rn, can't update much, wish me well soon
Upload Schedule: 2 chapters/day
Patreon Membership[1] can read 40+ chapters ahead.
Hiko x Ai - 60: Team V
.
.
.
Hiko x Ai - 101: Collaboration?
Hiko X Ai - 102: Sponsorship
Hiko x Ai - 103: Looking Away
[1] https://patreon.com/SmutCriminal69