Keiichi and his friends attend a game competition at a Sonozaki family owned shop. As a consolation prize for the event money, the store owner gives dolls to everyone except Mion. Keiichi gives his to Mion as he sees no value in keeping it. Later, Keiichi and his father meet at the cosplay restaurant. There, Keiichi meets Shion and confuses her for Mion, due to similar appearances. She proclaims that she is actually Mion's twin sister. Keiichi believes she is Mion pretending to be effeminate.

Keiichi learns about the yearly murders from Shion, Miyo, and Jiro. At the festival, Shion drags Keiichi away from Rika's dance and the two run into Miyo and Jiro, who are breaking into the ritual tool shed. They decide to go inside to look at it with Miyo.

Inside the sacred shed Keiichi learns about the dark origins of the Hinamizawa village and the Festival. The day after he finds out that Miyo, Jiro, and the village mayor have gone missing.

Rika has suddenly gone missing and Satoko coldly suspects Keiichi, who was the last one to talk with Rika, but Mion says that she saw Rika speaking with some men in construction uniforms. While looking for Rika, Mion pulls Keiichi away from a locked silo and indirectly informs Keiichi that Rika is trying to kill people and that she needs to put an end to string of murders occurring, which is being led by the Three Great Families.