お姉ちゃんの翠くん

Sui Sanae has always felt overshadowed by her perfect older sister, Momo, and her sister's charming boyfriend, Midori Yukishiro, only adds to her frustration. A college student with a knack for teasing, Midori treats Sui like a kid, much to her annoyance. But when Midori becomes her home tutor, Sui starts to see a different side to him—one that's unexpectedly kind and caring. As their time together unfolds, Sui grapples with feelings she never anticipated, caught between her loyalty to her sister and the stirrings of her own heart. (Unreviewed summary by Grok 2)