Watashi no Tadashii Onii-chan

A university student named Rize meets Kairi while working part-time at a supermarket. As she helps Kairi with sleep issues, memories of her older brother resurface, stirring feelings of affection. Rize becomes emotionally attached to Kairi, but her discovery of a diary in his apartment reveals disturbing information about a murder. Curious about the truth behind Kairi, Rize begins to investigate, driven by her growing emotions. The story explores themes of crime, mystery, and romance as Rize uncovers more about Kairi’s past.