Sword Art Online. Vol. 2 Fairy dance - Reki Kawahara

Kirito jumps into a new VRMMORPG called ALfheim Online (ALO) in search of Asuna,
who still hasn't regained consciousness. On his quest to find the World Tree and
reach Asuna, he meets a sylph girl named Leafa. A veteran player experienced
with the sword, Leafa recognizes that Kirito is motivated by serious
circumstances and decides to help him. But...Leafa's identity in the real world
is Suguha Kirigaya-Kirito's sister. And it's the glimmer of her beloved brother
she sees in Kirito that prompts her to lend him a hand. Now, despite the
conflicting interests guiding them on, the pair set off on a journey to the
World Tree!!