Kago no Tori

In a world where humans and bird-like beings coexist, a young man named Tori lives a quiet life in a rural village. He shares a close bond with his childhood friend, a bird-woman named Kotori, who possesses the ability to transform into a human form. Their peaceful days are spent exploring the forest and enjoying each other's company.

However, their relationship is tested when a mysterious illness begins to affect the bird-women, causing them to lose their human forms and revert to their animal instincts. As Kotori's condition worsens, Tori must find a way to save her before it's too late. The story explores the boundaries between love and duty, as well as the sacrifices one must make to protect those they care about.