After receiving a notice from the police, Hamase City Children's Consultation Institute learned that a boy was stolen in a convenience store.Natsui Ei (Haruka Fukuhara) and Masato Sosuke (Rin Chaodu) rushed to the convenience store and found that the mysterious boy (Chibakijiro) was the child Yi had seen on the street before.However, the boy did not name or explain, and he refused to put down his stolen drinks and sweet bread.

Yi and Masada temporarily placed the boy in the protection center.Minamino Cheng (Toshiro Yaya) noticed that the tired boy was holding a small toy model with the model saying Hiragana “ ㊚む” (Rhythm).

At the request of the children, Yi took them to a nearby shrine with Sunflower Kanata (Eriga Izuda).However, when the boy learned that they were going, he also asked to go together.However, while the children were playing, the boy suddenly shook his wing's hand and ran away.

At this time, Yi and others received a notice that a 10-year-old girl was arrested for taking a train without a ticket at a nearby station.It turned out that this was her third time taking a train without a ticket.What kind of secret is hidden behind the girl's repeated departure without tickets...