SWORD ART ONLINE: Memory Defrag is an action RPG in the style of classic Japanese anime role-playing games (RPGs), which allows players to play as the heroes of the popular manga and anime series from Japan known as Sword Art Online.

The app is based on the original manga series from Japan, in which the player takes on the role of a young man named Kirito, who has lost both of his parents and is being looked after by his elder sister, Asuna. Kirito meets another girl named Leafa on his way to reunite with his parents. The three of them become the core of the main cast.

Kirito, Asuna, Leafa, and other heroes from the original manga series have unique and distinctive personalities and characteristics. Each hero has unique abilities and skills, such as dual-wielding, one-handed swords, guns, bows, or magic.