Suguha: How did you all meet my brother?
Silica: When I was attacked by monsters, and Kirito-san rescued me. Then Kirito-san and I began an adventure to save Pina.
Asuna: I met Kirito-kun in a city called Tolvanna. Kirito-kun showed me, that there was joy in living, even in Aincrad. 
Lizbeth: He came in to my shop and broke one of my swords. Later, we fell into a dragon's nest and he threw dragon poop at me. Looking back, they're good memories.