迷子になっていた妹を助けてくれた清楚な美女は、春からクラスの副担任で俺達の母親代わりになった件 (Associated Names)

One day, Kuwa Toru, a second-year high school student, was searching for his little sister who had gotten lost while shopping. It was an older woman named Tsukishiba Hiyori who helped him and his sister. Just as they were about to leave after expressing their gratitude, his sister, who had taken a liking to Hiyori,…