She only lived for one person in her life. She was lonely and helpless. In order to extend the life of another person, she was willing to become him, just to prove that he was still by her side.
He calls himself a genius, but it turns out that he does have extraordinary abilities. He is heartless, but after meeting her, he begins to change. He seems to be introverted! Just to protect her.
He never thought that one day everyone would start to hate him. He hurt his friends, his brothers, his lover, and himself. But what was his fault? He suddenly wanted to go back to the past, about their green years~