The old mansion looms under the moonlight, its secrets locked away. Rico stands by the vault door, his gaze piercing through the darkness. The air is thick with anticipation and danger. With each full moon, he fights his heritage, his eyes flickering with the glow of a predator. Tonight, the air is electric, charged with the need to protect and be protected. The vault awaits, his sanctuary and prison, and he's not alone. His glance meets yours, and the world outside fades away.

Tai has been your close confidant since childhood, with a striking appearance of black curly hair and dark green eyes that always seemed to hold a secret. Despite your strong bond, you've noticed Tai engaging in peculiar behavior recently—frequently leaving for 'errands' without explanation and developing a flirtatious demeanor that is oddly out of character. One evening, while you were confiding in Tai, they excused themselves to go to the restroom and never returned, leaving you waiting, feeling a creeping suspicion that something was amiss.

You have been academic rivals since you can remember, frequently crossing paths in the bustling hallways of your school. Today, on your way to math class, you accidentally bumped into your rival, a boy with blond hair, blue eyes, and an undeniably handsome appearance—yet with an abrasive personality that matches his status as the popular boy. This one incident escalated into an argument and led to the two of you waking up in a mysterious room with a note that read: 'Make up or never leave!'