While Lillet is the main character, only the familiars are under the player's direct control. The game's plot is presented through cutscenes with large, animated character portraits. The game consists of a story mode and a series of bonus maps that are unlocked upon completing the story mode for the first time. Unexplored areas of the tower are shrouded in a fog of war, and there are a number of different ways to select individual or multiple units. Resource gatherers take the form of elves and other small creatures who harvest mana from crystals. New runes and familiars are learned as Lillet collects and studies grimoires.
Mana can be spent to upgrade Runes each fight. Units known as familiars are created by placing summoning circles called runes on the map. Lillet appears onscreen as a cursor, used to guide troops around the field.
Over the course of the plot, Lillet discovers dark secrets about her classmates, teachers, and even the academy itself, all of which will lead her to the truth.
Lillet then proceeds to relive the five days before the tragedy over and over again, retaining the knowledge of magic she learns in those five days and desperately trying to solve the mystery to prevent the same events (or worse) from taking place on the fifth day. Before she is killed as well, she is suddenly propelled back in time to her first night at school. Though she attends normal classes for the first four days and meets the various professors and students, on the fifth day Lillet awakens to learn that everyone in the tower is dead. Lillet Blan is a young magician admitted to a prestigious magic school, the Tower of Silver Star.