Fate is a young man whose job is to patrol the land around his village and protect it from monsters. One day, during such a patrol, Fate and his friend Shion encounter a mysterious girl in the nearby tower. She could only remember that her name was Rhianna, but nothing else about her origins and how she ended up being in that tower. Shortly afterwards, the village is attacked by monsters and burnt down. Fate, Shion, and Rhianna escape, and Fate promises Rhianna that he will help her regain her memory and find the truth about her past.

Tenshi no Uta II: Datenshi no Sentaku is not directly related to its predecessor story-wise (though it is set in the same universe, and some characters from the previous game make an appearance here). Graphically and gameplay-wise, it is nearly identical to it, with the exception of a few minor tweaks (such as characters regaining full health after level up): an archetypal Japanese-style RPG with random enemies, turn-based combat, linear story progression, and automatic character growth. Like the first game, Datenshi no Sentaku has a day and night cycle.