All of the characters in Touken Ranbu are bishounen anthropomorphisms of famous historical Japanese swords which are depicted as handsome guys, known as "Sword Boys" (刀剣男子 Touken Danshi). These personified weapons are based on real-life swords which are explained in detail within the game.
In the game, Touken Danshi are capable of becoming stronger as they gain experience and level up after battles. In the event when a sword's durability drops down to zero, it is considered broken, and the player will lose the sword boy. Players cannot resurrect swords that have been lost, and are only able to retrain the sword from scratch.
Upon the debut of the game, there were a total of 42 different swords available. Within updates introduced, additional swords have been added. The game holds spaces for around 150 different swords, so far there are a total of 45.