At first Kaguya was only interested in him as a swordsman who has an enigma, but later after seeing how much he cares about his comrades and her she starts to fall in love with him. She also affectionately calls him "Otōto" (
Kaguya has a very friendly relationship with Hikaru as her close friend as well as vice-president.
Kaguya was the first person ever to call Koyuki by her name, she is very fond of her and doesn't seem to care that she is an elf.
Kaguya likes Miō as well as everyone in Witch's House.