Kaori is one the most caring personalities in the series. She is a classmate of Hajime's back in their original world. She admires Hajime for his "strong" personalty and is the only classmate who pays attention to Hajime's existence in class even if she is popular in their school.
When summoned to another world, she receives the "Healer" job.
Kaori was unable to notice her lover for Hajime until he fell in the abyss which inspired her to become stronger in order to search for him. After reuniting with Hajime, she then joins their dungeon expeditions after confessing to him.