In a port town off the coast of the Kagawa prefecture lives a reclusive and cowardly boy in contact with the restless spirits that haunt the overworld. Near this town happens to be Onigashima, a purgatory situated on an island, a place that contains demons, reapers, spirits, and many yokai that make their home between the spirit realm and the living realm. Ghost Bite follows Sousuke as he accidentally finds himself in the social circles of these yokai, as they try to befriend him despite his overwhelming fear of them. The most persistent of which being Momo, a red oni girl obsessed with human culture and a penchant for the gorey consumption of lost souls.
The story opens on Sousuke sitting quietly at his classroom desk as his classmates excitedly chatter around him, idly gossiping about the party one of their classmates is hosting. Sousuke is startled as said classmate starts inviting him to the party, the classmate speaks quickly and cheerfully and Sousuke quietly panics as he tries to muster the courage to refuse. He ultimately fails and he shakily agrees and his classmate says they'll be on the lookout for him and chirps a goodbye, leaving to invite more classmates.
The scene then cuts to Onigashima, namely the Tasogare Spirit & Yokai Academy, an academy that not only acts as a school for young yokai but to also help newly passed spirits adjust to their new afterlife while their soul is in the Grim Reaper's sorting process. The scene focuses on Momo, Mifuyu, TekeTeke, Kiku, and Yuu all playfully chatting and tesing eachother. Yuu brings up a peice of gossip he heard from one of his living friends of a party happening in the human world and how he plans to go. Momo starts hastily asking him if there'll be any humans attending, which Yuu confirms. She then tells Yuu that she's tagging along and he happily agrees and invites the others along with them. Mifuyu denies as she says she plans to spend time with her girlfriend over the next few days and TekeTeke denies due to the fact she doesn't like humans. This leaves Kiku, which agree's after seeing how excited his sister is, while adding that he wants to eat some human sweets while there too.