Itsutsuko no Sofu - 五つ子の祖父

He is the maternal grandfather of the Nakano quintuplets and the father of Rena Nakano. He is the manager of the Toraiwa Hot Springs inn. ~!He later fell ill and passed away about three years after the main story and therefore could not attend his granddaughter's wedding with Fuutarou Uesugi.!~