Shirou Sakurai

Shirou Sakurai is the father of protagonist Shinichi Sakurai and the operator of a jujutsu dojo. Despite his impressively muscular build, his personality stands in stark contrast to his son's serious demeanor—he is carefree, fond of joking around, and takes particular delight in teasing Shinichi, showing little of the dignity one might expect from a father figure. In the second season, he drops a bombshell that had been kept secret from Shinichi for two full years: a younger sister had already been born without Shinichi ever knowing.