Suguha is Kazuto's adoptive sister in the real world, although later revealed to be his cousin. She is an accomplished kendo practitioner, having practiced for 8 years, following her grandfather's wishes. In ALO her avatar name is Leafa.
Suguha originally disliked VRMMO games for it hid peoples' nature and reality, as it did with Kazuto. She took up ALO in order to understand Kazuto better when he was trapped in SAO. She won the Sylph tournament, earning the title as the strongest Sylph before the events of the Fairy Dance Arc. She learned how to play ALO from her classmate, Nagata Shinichi. Suguha has become very good at ALO, because of the many years she has practiced kendo and the skills learned there were very effective for fights in ALO. She enjoys flying in the game so much that Recon even nicknamed her as "Speed Holic."