Seven, 七色・アルシャービン
from Sword Art Online
Professor Nanairo Arshavin, known as Seven in «ALfheim Online» (ALO), is a new, game-original character featured in the game adaptation, Sword Art Online: Lost Song. Nanairo's ALfheim Online avatar is a "Pooka;" A type of fairy who uses songs to boost her allies' stats in battle. Her in-game weapon is a large staff that she wields with both hands. Nanairo Arsharvin is the younger sister of Karatachi Nijika (Rain). During childhood, the two sisters lived together in their home in Russia. It was from Nijika that Nanairo learned many of the greetings that she would later use, such as "privyet". From an early age, Nanairo displayed signs of genius, which caused her parents to argue about their child's future. These arguments eventually led to the divorce of the parents. Using his authority, Nanairo's father obtained custody before taking her to America, leaving Nijika to return to Japan with her mother. In the real world, Nanairo works as a scientist, while in the virtual world, Seven acts as an idol songstress, promoting peace through her music. According to her fans, Seven writes the lyrics to her own music.

Sword Art Online
In 2022, a virtual reality massively multiplayer online role-playing game (VRMMORPG) called Sword Art Online (SAO) is released. With the NerveGear, a helmet that stimulates the user's five senses via their brain, players can experience and control their in-game characters with their minds. Both the game and the NerveGear was created by Akihiko Kayaba. On November 6, 10,000 players log into the SAO's mainframe cyberspace for the first time, only to discover that they are unable to log out. Kayaba appears and tells the players that they must beat all 100 floors of Aincrad, a steel castle which is the setting of SAO, if they wish to be free. Those who suffer in-game deaths or forcibly remove the NerveGear out-of-game will suffer real-life deaths. The main character, Kirigaya "Kirito" Kazuto, was also one of 1,000 testers in the game's previous closed beta. With the advantage of previous VR gaming experience and a drive to protect other beta testers from discrimination, he isolates himself from the greater group and plays the game alone, bearing the mantle of "beater", a "beta tester" and "cheater". As the players progress through the game Kirito eventually befriends a young girl named Asuna Yuuki, who form a relationship that later turns into in-game marriage. After the duo discover that Akihiko Kayaba was playing the game as the leader of the guild Asuna joined, they confront and destroy him, freeing themselves and the other players from the game.