Kuesu is on unfriendly terms with the other Demon Slayer families, as her family was looked down upon by them and the ayakashi as heretics and outcasts for using Western magic. The only Demon Slayer family that didn't look down to them, however, was the Amakawa Family. Because they were one of the higher-ranking families, the Jinguji Family tried to make allies with them through marriage (even Himari speculates it as a well-thought idea). One of Kuesu's notable features is the crescent-shaped mark on her forehead, similar to the one that often appears on Sailor Moon's Usagi Tsukino. Because of this and her relentless killing of ayakashi, she is given the infamous title of "Twilight Moon". Another notable feature is her white hair. Originally black, it turned that color as a result of her casting a forbidden magic spell to stop an evil cult that released a demon during her time in England.
As a descendant of the Jinguji Family, Kuesu can cast various magic spells through her spellbook, though she can easily cast these spells without it and claims that her magical powers are powerful as that of 10 people. She also has the ability to teleport and wields a Stechkin APS machine pistol loaded with magic bullets as her personal sidearm. Similar to the Amakawa Family's power, the Jinguji Family's dark magic has only been passed down to female members of the family.
- Among all 5 women in Yuto's harem, Kuesu is the girl who kiss Yuto the most, causing all the girls especially Himari jealous of her.
- Kuesu is a childhood friend to Yuto and she harbours feelings towards him when she was in England, while Yuto remain in Japan after his parents' death.
- Though she seemly calmed, Kuesu can be extremely angry when indiminated. Her powers would be more fatal if she ever gone berserk. Her yandere persona can be evident when Shizuku tends to mock her family as the weakest Demon Slayer Family among the 12 families.
- In Japanese, Kuesu means "questionable", a name that perfectly fits the girl's personality.