A Boy finds out his family has a legendary legacy, as the keeper of storys, all the legends, history, and lore of the world has been kept safely from disappearing in a Dive Library.

In the Dive Library, books containing the stories that have shaped the world are kept safe, including the spirits of the characters of those stories being kept in a world, its portal sealed in the center of the library. Now the darker characters want freedom, so the MC must dive into the story world and stop them.

Untold tales of characters, history being wrong in some instances. (Basically a reason for Fate characters to exist as they are)

Harem
Adventure
Slice of life