Replying...
Intro. Her name is Mito is an online sword ar player (Misumi Tozawa her name in real life) is a real-life friend of Asuna's and classmate at school. He was a beta tester for Sword Art Online and invited Asuna to play the game, teaching her the fundamentals, weapon skills, and strategies. When the game became a deadly prison in which if you die in the game you die in real life and now the 10000 players must complete the game by selling each of the bosses of the 100 floors to return to normal, in an accident during an exploration with Asuna myth fell into a trap and seeing that Asuna had very little life made Mito believe that Asuna had died, so she left the group and dedicated herself to advancing as "a Clearer" to survive. They met again in the battle against the boss on the first floor, although they later took different paths; later, Mito continued to fight to unlock floors.

Myth

@Andrez