The setting is Astrea Academy, established in the Kingdom of Astban. This is a meritocratic institution where those lacking ability are relegated to poverty, while those with talent rise to wealth (though favoritism based on bloodline still exists).

S-Rank: Only those ranked 1st to 4th. There are barely enough to count on both hands in the entire country. Falsifying this rank is a capital crime. S-Ranks are true powerhouses who cannot reach this level through bloodline or connections alone. A-Rank: A level achievable through favoritism if one's lineage is superior. Composed more of the powerful than the talented. B-Rank: Ordinary and boring. They neither stand out nor pay attention to others. C-Rank: Often recruited by A-Ranks as slightly useful slaves. They essentially have no right of refusal. D-Rank: On the verge of expulsion. Those remaining are either academically gifted or lost their chance to rank up after being enslaved on the first day.

Duels can be initiated. If the challenger's rank is higher than yours, the duel is mandatory; if they are lower, you may refuse. If you lose a duel, your "human rights" are transferred to the opponent.