Koyomi enters the classroom against Hanekawa`s advice and talks to Sodachi, who has a venomous hatred for him, and he cannot believe that it comes simply from the class meeting two years ago, as she enigmatically mentions that he has no idea what makes him what he is, as he cannot remember what was in his shoe locker the first year of middle school. She winds up stabbing him in the hand with a pencil just as Hitagi comes in, although Hanekawa is tying to stop her, and the two have a fight.
Later, Ougi accompanies him to his former middle school, and they go to his old shoe locker, which contains envelopes with his name on them. One of the envelopes contains a map, which leads to a dilapidated old house where Koyomi remembers that he explored regularly every summer during middle school, and where he met a girl.