Replica Datte, Koi wo Suru.

In the anime Replica Datte, Koi wo Suru., a mysterious girl exists solely to serve as a substitute for a high school student named Sunao. Created from Sunao's own wish, she appears on days when the original cannot attend school, living a life where no one knows she is a replica.

Her hidden existence is challenged when she strikes up a friendship with a perceptive classmate, Sanada. He is the first person to notice the subtle differences between her and the real Sunao. To maintain their unique connection, she establishes a simple rule: he may only interact with her when her hair is styled in a half-up fashion.

As their secret meetings continue, a delicate bond forms, leading the replica to experience emotions she never anticipated. This poignant story explores themes of identity, existence, and the nature of love, as she grapples with the profound question of what it means for a copy to develop genuine feelings for someone.