Usually calm himself, Shūei likes to tease others, and claims to be Kōyū Ri's best friend though Kōyū keeps denying it. Shūei and Kōyū met during the Imperial Exams, in which Shūei took the second highest honor as Bougen. The two men become reacquainted after being assigned by his superior (Koku-Daishogun) as the personal guard and advisor respectively to Ryūki, who disappeared and left Shūei and Kōyū in the library for a month of boredom. Shūei enjoys provoking Kōyū, usually by mentioning the latter's lack of direction and his aversion to women. Unlike Kōyū, Shūei enjoys being a popular ladies' man, often visiting the courtesan Kochō. However, Shūei's womanizing habits are mainly to attract the attention of Shusui, who finds his behavior irritating and likens it him to treating the Imperial Harem like the Red Light District. Unknown to Shusui, Shūei had fallen in love with her during their first meeting after she had helped him. Shūei is also a frequent visitor at Shūrei's house and he often pays for the ingredients every time he dines there, resulting in Seiran calling him "saifu #1" (wallet #1).