When Sky Meets Earth, Fire, and Sea

Travelling back to her mother's home country called Elcielo, Allesky Zerclaire had hopes to start anew being able to flee from her father's iron fist back in Armonia just after the death of her beloved mom. She found a refuge place in the old mansion of her late grandfather in the province but her still short stay was disrupted by a strange man in this black attire the next morning. Allesky didn't know who that man was but she had no choice but to come with him to a secret organization which was introduced to her as Apoptosis further informing her that she is the sole individual who was found positive in the Trial Zero Test, of which Allesky had no idea about. These strange suits and weapons, the enhanced abilities and skills, the new technology, and the new secret identity she had found. It turned out that she was brought to a secret world -- that being kept from the outside community for generations -- the world of agents, special identities, and secret organizations. She meant to live a peaceful life away from her father and to get by the tragedy that loomed in their relationship but what she got in Elcielo is on a whole new level to handle -- especially to wear the identity she never have thought of owning ever in her life. It's time to be an agent to protect herself first and foremost. What adventures and dangers await as Allesky fulfills the role of being the most valuable agent plus getting along with the famous trio of Apoptosis?