Hitsuji no Uta

An unsettling reaction to blood sends Kazuna Takashiro back toward the family he barely knows. Reuniting with his older sister Chizuna brings an explanation he would rather not hear: the craving is an inherited illness, and she has lived with it for years.

As ordinary friendships become harder to maintain, Kazuna finds understanding in the one person who shares his condition. Their growing dependence offers shelter from the outside world, but the family history surrounding them makes that shelter increasingly fragile.