Ichirō Mamiya (間宮 一郎 Mamiya Ichirō) was a famous painter who disappeared in his mansion 30 years prior to the events of Sweet Home. His disappearance is believed to be connected to his wife's suicide. He painted 24 frescoes throughout his home, which can be photographed by Taro to reveal hints and bits of backstory.
The five protagonists visit his mansion to make a documentary about his life and works.
- It is suggested by the game that the character Yamamura is, in fact, Ichirō Mamiya in disguise.