Fuku takes up the appearance of an elderly, but capable man. He has a wise semblance surrounding him, with noticeable wrinkles on his face from age. His hair is grey, and swept back, revealing his forehead.
He is most often seen wearing a blue jinbei with beige socks and sandals.
He is kind and lenient with his granddaughters, responding to their needs and curiosity with a relaxed tone in stark contrast to Mamedai, who is harsher with the girls. He is also very laid-back and has a tendency to not panic much as seen when he had accidentally choked on mochi to the point he had to be rushed to a hospital, wherein he'd simply behaved as if it was nothing.
Though not much of his past is known, it has been said that he decided to construct a mochi shop because his grandfather had been a mochi maker as well.
Not many skills of his are known, but it has been established that he is well enough in the task of mochi-making.
- Mamedai Kitashirakawa: Mamedai is his son, and they appear to have a normal relationship. Mamedai refers to him as "the old man", and has been shown to be exasperated with his father's flexible and mild mannerisms. Nonetheless, Mamedai had rushed to the hospital when hearing his father was submitted there.
- Anko Kitashirakawa and Tamako Kitashirakawa: The two girls are his granddaughters, and he doesn't hesitate to answer their questions. He doesn't behave very strictly with them, and Tamako appears to care for her grandfather very much as she had been driven to tears when watching her grandfather being pulled into the ambulance.
- His blood type is O.