Sayonara, Otoko no Koさよなら、おとこのこ ; Sayonara, Otokonoko

One day, 25-year-old Hajima Kanade wakes up to find himself in a child's body. While his live-in lover Kawata Yuuki freaks out, Kanade tries to take it as calmly as possible. Before they are able to figure out what to do, Yuuki's younger brother knocks on their door. Will Kanade be able to keep his cool?