The cute art style is a deliberate trap. The show uses your comfort with these characters to make the violence hit like a physical blow, when it comes, you're not ready, and that's the entire point. Hinamizawa seems safe until it doesn't, and by then you're locked in a mystery that demands you rewatch everything to find the answer you missed the first time.

Keiichi Maebara moves from the city to the rural village of Hinamizawa in the summer of 1983 and quickly settles in, spending his school days playing games with new friends Rena, Mion, Satoko and Rika. Then he learns of a gruesome murder in the village. As the annual festival approaches, he discovers a string of killings and disappearances in recent years that seem tied to the festival and to Oyashiro, the local patron god. When he asks his friends about them, they fall silent, and Keiichi begins to wonder what else they are hiding and whether he can trust them at all. As paranoia takes hold, the mystery reaches back to events five years earlier. Adapted from a murder mystery game by 07th Expansion, the psychological horror story unfolds across several separate arcs.