A swordsman who met F91 while he was training and honed his skills together. Ryuusei was summoned by Goten Gundam together with F91 and was given the "Armour of Rekkuu" and renamed Rekkuu Gundam. He is cheerful and at first glance appears to be carefree, but he is a hard worker who never stops working when no one is looking and has a strong sense of justice. When he sees a strong opponent, his swordsman blood boils and he cannot help but challenge them to a fight, and he will face any evil head-on. It is said that no one other than his clan can master the long sword Tsubasa Shinmaru, which releases shock waves that cut through the air.