心が傷ついた隣のお姉さんを助けた結果、盛大に病んで愛された件 (Associated Names)

The protagonist, an ordinary high school sophomore, has a woman on his mind. She is a woman who lives in the next room in the same apartment building, a beautiful and stylish older woman. He wants to get close to her somehow, to talk to her more, but she has a boyfriend. So the main…