The Mononoke Lecture Logs of Chuzenji-sensei: He Just Solves All the Mysteries

Three years after the WW2 ended, second-grade high school student at the time, Kanna Kusakabe solved a ghostly disturbance at her school with the big help of Mr. Chuzenzi, a strict yet book-loving teacher. After that, she often seeks his advice and starts to interact with his kind family and his funny friends. (imdb.com)