Seiyoku Shori ni Tsukatteita Imoutou to Irekawatta Ani

Kou's working at home every day with only his sister to keep him company. When his stress finally hits a wall, he explodes and pounds that stress into her! An accident leads to them bonking heads and now… wait… something's wrong. Kou's looking at himself from Riko's body… **Official English:**.