21 Nichigo ni Share House shiteiru Senpai to Fuufu ni natte shimau MonogatariNijuuichi Nichigo ni Share House Shiteiru Senpai to Fuufu ni Natte Shimau Monogatari; 21日後にシェアハウスしている先輩と夫婦になってしまう物語; 21 Nichigo ni Share House shiteiru Senpai to Fuufu ni natte shimau Monogatari; 21-nichi-go ni Sheahausu Shite Iru Senpai to Fūfu ni Natte Shimau Monogatari; A Story About Becoming a Married Couple After 21 Days Living in a Share House with My Senpai; 21天後跟合租房的前輩結爲夫婦的故事