Father of Kenshirō Kasumi and Ramon Kasumi. He was the 61st successor of Hokuto Shin Ken. As a young man he sought to fight Liu Xuanxin in the Tenju no Gi challenge but Liú had became to old to fight. Tesshin fell in love with his daughter Liu Yueying and they conceived a son, Kenshiro. Tesshin once fought Wei Ruiying, founder of Kyokujūji Sei Ken, to a draw but received a big cross-shaped scar on his back. He remarked that Ruì-Yīng may have been able to defeat him had he not lost a leg. He also beat the hermit Lǐ Sǎn's Shadowless Kick. For reasons unknown, Tesshin never told Kenshirō about his homeland (China) or his mother.