At St. Lucia Academy, the body of a male teacher has been discovered in the pool. The girl who found him, Mizuho Kousaka, is a shy bullied student who seems relatively unaffected by her discovery. After all, this isn't the first time she has seen a corpse.

In order to teach Mizuho to stand up for herself, a girl named Shion Sonozaki befriends her and the two become inseparable, as they both share traumatic pasts. But when another body is found, Mizuho comes under suspicion for murder. It's up to Shion to protect her new friend in Utsutsukowashi-hen, a side arc to the main Higurashi storyline that explains some of Shion's time at St. Lucia Academy.

Also contains epilogue and the "Upside Down" chapters from Onisarashi-hen.