The Little Sparrow Murders — Seishi Yokomizo

An old friend of Kosuke Kindaichi's invites the scruffy detective to visit the remote mountain village of Onikobe in order to look into a twenty-year-old murder case. But no sooner has Kindaichi arrived than a new series of murders strikes the village - several bodies are discovered staged in bizarre poses, and it soon becomes clear that the victims are being killed using methods that match the lyrics of an old local children's song... The legendary sleuth investigates, but soon realises that he must unravel the dark and tangled history of the village, as well as that of its rival families, to get to the truth.