During a class assignment, a vase in the cabinet seemingly breaks by itself, but there's an elaborate plan behind it. However, this mystery is quickly forgotten when Osanai sees the bicycle thief again and plots revenge.

Kobato finds Osanai crying in the school hallway, but she runs away without telling him what happened. At the student newspaper club, a new mystery involving Berliner Pfannkuchen (jelly doughnuts) awaits him.

Just before a date with Osanai, Kobato runs into Kengo, who shares some disturbing news and leaves a strange message. Together with Osanai, Kobato tries to solve the mystery. However, shortly after, it appears that Osanai is in great danger.

When Kobato goes to visit Osanai at her home to invite her to eat candied apples, he learns that she has been kidnapped. Just as he leaves the apartment, he receives a mysterious message from Osanai and, with Kengo's help, sets out to find her.

There will be a change of pace in the school newspaper. Kobato shows an interest in serial fires.

Urino's rules spark escalating arson; Hiyori supports him while Osanai gives advice as bonds shift.

Urino and Kobato both arrive at the site of the final fire.

Kobato wakes up in the hospital and sees a box of chocolates with a message from Osanai.

Kobato finally manages to see Osanai in the hospital, revealing a sinister and terrifying truth.