Sakurako-san no Ashimoto ni wa Shitai ga Umatteiru S01E10 - The Butterfly Vanished in November, Part 1

The year's final bone gathering expedition is cut short when Isozaki informs Sakurako and Shoutarou that one of his former students, Hitoe, has gone missing. In the past, Hitoe's friend, Futaba, had similarly gone missing on Isozaki's watch as their homeroom teacher...