Angel Hearts is a dead simple RPG developed by ELF in 1989. The gameplay resembles that of "dungeon crawlers", meaning that there are no friendly areas; though the view for exploration is top-down rather than first-person (which is reserved for the turn-based battles). The gameplay mechanics are mostly confined to fighting random enemies and earning enough experience points to go up a level and standing a chance against the next "boss" enemy. There is no equipment system, and battle commands are restricted to "Attack", "Escape", and "Item".

In a certain girls' high school, students have begun to mysteriously disappear. Authorities suggest that a secret society is at work. A spy needs to be sent in order to solve the mystery, and this mission falls into the hands of this game's hero. His boss explains to him that the quest is dangerous, indeed: many students associated with the mysterious cult have gone rampant and will attack any trespasser on sight!