First appearance: Battle 6
Type: Dou/Sei
Type: Katsujin Ken
Martial Arts: Given his abilities, likely proficient in everything (as evidenced by his capacity to effortlessly mimic all of an enemy's techniques)
Hayato is Miu’s grandfather and the undefeated elder of the Ryōzanpaku Dojo. He is famed for defeating 500 Shaolin masters nearly to death. Known as the "Invincible Super Man," his kicks are so swift that even slowed down a thousand times on replay, they remain indistinct. When needed, he can intimidate other masters to preserve peace. Using just 0.0002% of his power, he can easily overpower both Kenichi and Miu simultaneously and split a tree in half. He once defeated a master-level opponent in the D of D tournament with a single finger. Before establishing the dojo, he traveled the world with his granddaughter in search of peace. He has developed 108 special techniques and can replicate any move used against him, including Kenichi's "Saikyou Combo" and "Saikyou Combo 2," Soutenshu, and Miu’s "Hyōi Kazekirihane." He knows Seikūken and created the "Ryūsui Seikūken," which Kenichi learned from him. His most frequently used technique appears to be the "Human Shuriken."
A move shown in the manga is the "Shockwave of Forgetfulness," which erases memories. He seems able to control how much memory is lost; in a flashback, the thug leader experienced total amnesia after meeting Apachai, while Kenichi only lost his short-term memory.
His training methods are the most terrifying among the Ryōzanpaku masters. During Kenichi’s mountain training with him, ominous events like cracked tea bowls, pots, and chopsticks were common. Hayato affectionately calls Kenichi "Ken-chan" and is the sole master who apologizes for the brutal training he and others put Kenichi through. He later notes that Kenichi reminds him of his younger self. Though seemingly invincible, Miu reveals Hayato struggled against Silcardo Jenazard before. He and Kushinada have known each other from the past.
Despite being the eldest and strongest at the dojo, Hayato can be rather irresponsible. He recklessly spends dojo money on personal items and gets carried away when showcasing his strength. Sometimes he is seen eating candy, especially lollipops. He also mentions feeling weaker. After using 0.0002% of his power against Miu and Kenichi, he said he needed rest. In Battle 231, he demonstrates bi-vocal skills allowing him to speak in two voices simultaneously, even performing a karaoke duet. He can use different sides of his body for separate actions and reduce his voice so only one person hears it. These abilities lead many to believe he isn't human.
