The Sumiya Incident refers to violent acts which Kamo SERIZAWA, head of Shinsengumi (a group who guarded Kyoto during the end of Tokugawa Shogunate), carried out during a party held in ageya (a restaurant where high-class harlots and geisha dispatched from a geisha house entertained guests) called Sumiya in Shimabara, Kyoto in June, 1863.
角屋での暴挙（すみやでのぼうきょ）とは文久3年（1863年）6月、京都嶋原の揚屋・角屋（すみや）にて催された宴会で、新選組局長芹沢鴨が働いた乱暴狼藉をいう。