Mizar is a world filled with corrupted creatures and humans. And though most people are adjusted to the mysterious magic that causes this corruption, not all are aware of it's effects on regular animals. Heart Adoption follows the journey of a magical bird breeder named Robin and his attempts to keep his sparrow adoption centre afloat. But will Robin, together with his new apprentice Ace, be able to manage these corrupted birds that seem to grow stronger with each passing day?