Sankarea is about a zombie-obsessed boy, Chihiro Furuya, who discovers how to resurrect the dead and as a result acquires a zombie girlfriend when the 15 year old girl he likes, Rea Sanka, dies in an accident but is brought back to life thanks to having earlier drunk a potion he had developed using information he got from an old manuscript.

Hydrangeas feature prominently in the story as the zombies need to eat them to keep body and soul together (literally!)

Ironically Rea had actually drunk the potion as a suicide attempt, as one of its ingredients was the poisonous plant Hydrangea (also known as Hortensia). She had come to despise her overbearing and abusive father and when he withdrew her from school so as to completely control her life, she decided to end it all. Unfortunately, her death does not free her from his continued interference in her life!