Head of the 4th Generation Front of Armament and former Vice-Head of the 3rd Generation. 18 years old, a high school senior. While there are no depictions of him in school or clubs, most TFOA members are in their teens (retired members are now adults). He has long black hair, a husky voice, and tattoos on both shoulders. He is always seen wearing a leather riders jacket and sunglasses. A master of boxing, he possesses enough skill to easily overwhelm Pon and Hiromi even when they double-team him, though he lost his first one-on-one fight against Harumichi to a rear naked choke. Later, he lured Harumichi out by taking Yasu hostage, but seeing Harumichi arrive alone made him question the methods of his older brother Hideo (the 3rd Head). He challenged Harumichi to a second fair fight but lost again. After the 3rd Generation collapsed, he invited Juzo Murata to be his Vice-Head and gathered a total of 13 men—including Giichi Samejima, who had distanced himself from the 3rd Generation's inner circle—to reform the Front of Armament as its 4th Head. Unlike Hideo, he is deeply trusted by his comrades. He changed the group's attire from the previous jumpsuits back to the leather jackets of the first generation. He came to be known as one of the "Four Kings," alongside Harumichi Bouya of Suzuran, Osamu Furukawa (Bull) of the Kurotaki Alliance, and Tatsuya Bito of Housen Academy. In the past, he suffered a helpless defeat at the hands of Tatsuya Bito when Tatsuya was still a middle schooler, leading to a mutual rivalry, though their current skills are evenly matched. Following the incident with the trio from the south of the prefecture, he became sworn brothers with Teru. When Teru was stabbed during an ambush by the Snake Heads, Ryushin headed south with Harumichi, Bito, Bunta, and Ryota, eventually becoming a member of P.A.D (Paruko and Dangerers).