第4話: けいはひかりを自宅に招き、弟のすいを家庭教師として雇い、関係改善を図る。

4

Kei invites Hikari to his house because his father wants to talk about pro-wrestling with someone. She unexpectedly becomes a tutor to Kei's younger brother, Sui, who has a rather strained relationship with Kei, and tries to bring the brothers closer together. (Source: Wikipedia)