Suikyou Date

The grandfather of Mapko, he is a vigorous elderly man known for his love of Go and remarkable physical fitness. Despite his slender appearance, he conceals an astonishing six-pack abdomen beneath the surface. Easygoing by nature, he once took in the down-and-out leader of a certain organization, Kuroma, off the street—and remained entirely unaware as his own basement was quietly converted into that evil organization's secret headquarters.