Adrien, along with 10,000 other people buy the new virtual reality game Sword Art Online. Original a Beta Tester for the game, Adrien has no problem navigating the game under the username, Chat Noir. When a friend he met through the game unsuccessfully tries to log out, they find out from the game's creator that the logout feature has been removed and if they were to die in game, they would die in the real world. In order to escape, they have to beat all 100 levels of the game.
Many players agree to take down the first level boss, Adrien pairing up with a girl named Ladybug. Due to their successful teamwork, they beat the boss, although people look down on Adrien because he was a beta tester that didn't help the new players after everyone discovered they were trapped in the game.
For two years Adrien mostly flies solo during the game, occasionally partying up with different people. He eventually meets Ladybug, who is a high ranking member in the largest guild in the game. They form a good friendship which eventually turns to love, and they decide to marry in-game and retire from the guild. Shortly after they are called back to the front lines against the 75th floor boss. Adrien discovers that the guild leader was actually the game creator, and challenges him to a duel in order to free everyone from the game. Ladybug and Adrien win, nearly dying in the process. As they watching everyone return home, they reveal their names and promise to find each other.
The second part of season 1 never happened. Or anything after that.
Whose Who:
Kirito - Adrien/Chat Noir
Asuna - Marinette/Ladybug
Yui - Manon
Ryoutarou - Nino