Niji Iro Togarashi

After the death of his mother, Shichimi sets out to join his half-brothers and -sister who live together in Karakuri Tenement, a place provided by the father they have never met.[2] He finds out that each of them had different mothers (all of whom have died), but were fathered by the same man. Not long after Shichimi's arrival, the siblings decide to journey to visit the graves of each of their mothers. On this journey, they encounter many dangers.

From: Wikipedia