How Could My Sweet, Gentle Childhood Friend Be a Yandere?

When Shen Yanzhou was six, he gave Wen Zhi a piece of candy.

From then on, she only had eyes for him.

But he only ever saw her as a little sister. She was afraid of the dark, so he stayed with her. She called him big brother, and he answered. She chased away every girl who got close to him, and he never noticed.

Later, they moved into the same apartment. Every night, she hugged a pillow and knocked on his door. Every time, he left it open.

He thought she was just afraid of the dark.

Until she said, "Big brother, you can only belong to me."

Childhood friends / Yandere heroine / Sweet romance / Cohabitation / Happy ending