Misumi Tozawa, known as Mito within Sword Art Online, is a movie-original character created for "Sword Art Online the Movie -Progressive- Aria of a Starless Night." In reality, she is a classmate and close friend of Asuna Yuuki, forging a meaningful bond despite their contrasting personalities. Academically gifted and ranking higher than Asuna in tests, Misumi is also an avid, skilled gamer who frequents arcades, drawing crowds with her gameplay. Her gaming interests and academic reputation limit her social circle, leaving Asuna as her only genuine school friend. Their friendship includes shared gaming sessions and personal moments like braiding each other's hair. Mito introduces Asuna to Sword Art Online by inviting her to play together, altering Asuna's original spontaneous login from the main series. Inside SAO, Mito's avatar significantly differs from her real-world appearance, reflecting her preferred gaming persona. After players become trapped in the death game, Mito leverages her beta-tester experience to guide Asuna, leading her from the starting city to optimize survival through strategic leveling and resource gathering. She acts as both mentor and emotional support, helping Asuna process their traumatic situation and find enjoyment in monster hunting and exploration. A critical incident occurs during a battle against nepenthes monsters. Mito temporarily leaves to capture a rare creature, during which Asuna inadvertently triggers a monster swarm. Witnessing both their health bars critically low and unable to reach Asuna in time, Mito disbands their party and flees. This abandonment leaves Asuna vulnerable to a subsequent attack, nearly causing her death before Kirito intervenes. The incident inflicts significant psychological distress on Asuna, leading to depression and trust issues, while Mito avoids contact fearing confirmation of Asuna's death. They reunite during the strategy meeting for the first-floor boss raid against Illfang the Kobold Lord. Asuna initially avoids confrontation, but after discussing the abandonment with Kirito, she gains perspective on Mito's fear-driven decision and reconciles. During the boss battle, Mito reduces Illfang to his final health bar, defends other players, supplies Asuna with a rapier, and assists Kirito during a critical recovery moment. Post-victory, Mito apologizes. Asuna declines her offer to rejoin as a party member, choosing instead to follow her own path alongside Kirito. Their parting remains amicable, with Mito respecting Asuna's newfound independence.