A hero is made of H and Ero.

(Source: MU)

After the meteorite "Artemis" collapses on the moon, an unidentified phenomenon affects humans: the "Reproductive system disease". 12 years passed and mankind has done research in the field of cloning and immortality in this world where the birth rate is 0. Meanwhile, Ashiro Koshiro is still seeking the cause of this disease, and suddenly a woman appears and gives him a mysterious suitcase...

Kibayashi Rento is a 'personification' of a supernatural being descended from a family of Ents (tree-oak people). One day his arm got torn off trying to save a cat from a tree. While he's looking for the arm, he crosses a girl, Kurashina Saya, who finds his lost arm. Saya is Rento's crush, and actually a fellow 'personification' descended from a family of Ghouls, whose main characteristic is appetite for humanoid meat. Can romance blossom between the two supernatural beings?

Slight discomfort advised. Don't worry though because he's a plant, so he can regenerate his lost body parts easily, including that aforementioned arm.