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.

To top off their summer sweets tour around the city, Osanai treats Kobato to a Tropical Parfait as thanks for rescuing her. Along with this delicious treat, Kobato is also served the whole truth about Osanai's kidnapping.

After a long conversation, Osanai and Kobato come to the conclusion that their agreement has failed – and with it, their friendship. From then on, they go their separate ways.

After starting to get involved with Osanai, Itsukaichi investigates a possible string of fires in the city.

In the hospital, Kobato thinks back to the circumstances around Hisaka's car injury in middle school.