Sasaki and Miyano - S01

After coming back from a field trip, Yoshikazu Miyano and his friends prepare to take charge of the Discipline Committee. But when a student loses their keychain, former chairman Masato Hanzawa seizes the chance to form the First Lost Item Detective Squad and track down the missing item. Meanwhile, Shuumei Sasaki struggles to figure out where his relationship with Miyano stands. Wanting to support him, Sasaki joins the search-but even with his help, the investigation hits a dead end. The group must keep searching and unravel the mystery of the keychain quickly, as they realize more items have started disappearing.