None of the six Miyanomori brothers has managed to become the new head of the family after the latest competition, so their grandfather Genichirou has announced he will hold the competition again. He also brings a seventh brother—Mamoru—into the family home for the first time, adding a new dynamic to an already complicated inheritance dispute. The title Gentou Nostalgie refers to the Kinema Mosaic mode within the game, which offers three playable perspectives: second-year mode, epilogue mode, and informant mode.