Doukyo shitara, Byou de Taberaremashita. Shuuchaku-kei Osananajimi no Hageshime Ecchi

Yukiko is a young woman who teaches calligraphy to children, and has dinner with her next-door neighbor and childhood friend, Megumi. One day, Yukiko's life is turned upside down when she finds an eviction notice in her mailbox. As luck would have it, Megumi's hospitalized mother invites Yukiko to live in their house, since she can't bear to see her son living alone. Yukiko is overjoyed at the chance to eat Megumi's cooking every day and relive the happy sleepovers of the past, but Megumi himself is less than pleased with the arrangement. While Yukiko sees him as her younger brother, he has deeper feelings for her, and wishes she would see him as more...When Yukiko is evicted from her home, her childhood friend's mother invites her to move in with Megumi. Yukiko is clueless about Megumi's feelings for her, causing Megumi to grow ever more frustrated, until he can't contain himself...

(Source: Renta!)