Yakiimo is a youmu that Mitsuki is keeping as a pet. The name means sweet potato and it's based on its appearance.

They should never have met. They shouldn't even exist. But when they come together, the entire world will change. The last surviving member of her clan, Mirai Kuriyama is cursed with the terrifying ability to control and manipulate blood, a power so heretical that she is shunned even by those with the ability to understand her "gift". Akihito Kanbara is only half human, but while the monstrous other half of his lineage seems to have doomed him to a life alone, it has also given him near invulnerability in the form of rapid healing. Alone, their futures seem bleak, but when a chance encounter brings them together, it becomes clear that they share more than just an unexpected bond. Together they share a destiny and a mission that only the two of them together may be strong enough to survive.<br>
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(Source: Sentai Filmworks)

Chibi Angels of the female cast members holding a trial for various characters from the series.

This is the first part of a two-part movie. The story is a recap of the TV series.

This is the second part of a two-part movie. The story takes place one year after the TV series.