Maigo ni Natte Ita Youjo wo Tasuketara, Otonari ni Sumu Bishoujou Ryuugakusei ga Ie ni Asobi ni Kuru You ni Natta Ken ni Tsuite

One day, Charlotte Bennett joins Akito Aoyagi's class as a student studying abroad. Everyone in the class is attracted to Charlotte's beautiful appearance and elegant demeanor, but Akito feels like "we belong in different worlds" and stays away.

However, Akito's daily life drastically changes when he rescues Charlotte's younger sister, Emma, when she got lost. He finds out that the Bennett sisters live in the apartment next door to his, and since Emma had taken to Akito, the Bennett sisters start coming over to Akito's place every day. The three of them play dominoes, sit around the dinner table, and go out together. As they spend time together, Akito and Charlotte grow closer, in their own clumsy way…

(Source: NicoNico Seiga, translated)