Tozawa Rio, who considers herself an average high school girl, is persuaded by her friend and fellow streamer, Onodera Eriko, to begin streaming the VRMMO "Break World Online" under the alias 【RIO】. The game, which boasts a mix of innovative and classic features, is nearing its third anniversary.

Though streaming, Rio is resolute about remaining an amateur, with no ambitions of becoming a professional. Her true motivation for playing stems from a deep desire to rise to the top of the player rankings in a virtual world, a place where she hopes to escape the ordinariness of her real-life existence.

However, Eriko's viewers, who had been directed to Rio's stream, were all universally astounded.

The reason was Rio's utterly unconventional playstyle, a complete departure from what one might expect from an average high school girl, and something wholly unsuitable for streaming. Leveraging her selection as a "Vampire"—a race known for its tricky, hard-to-master abilities and antagonistic relationship with humanity—she immediately began unhesitatingly slaughtering resident NPCs, transforming them into her loyal subordinates, and aggressively pursuing a G (Genocide) route through villainous role-play from the very start of the game.

Becoming stronger by consuming blood, Rio aims to dismantle the dystopia of hypocrites.

Through these villainous role-play streams, RIO soon began to attract a growing audience of former players, individuals whose spirits had been crushed by the game's community and who had been driven to abandon it.