Z: Endless Hope

Komori, a male patient at a hospital falls in love with a nurse, Hina. However Hina turns into a zombie. Komori keeps Hina in a room, tries to support her but one day he finds out Hina use to date with a married doctor.

Two junior highschool boys go into an abandoned building where they get attacked by a zombie. They manage to run a hospital in a city but on the top floor, there are other adults who also ran away from zombies.

3 years after the Zombie pandemic, zombies were recognized as "Z" and the Japanese government announced that they managed to confine all the zombies.