The white swindler who once deceived Hitagi and the cause of Nadeko's curse. Kaiki is a capable conman, able to deceive multiple people to get the results he wants, usually being money. On one occassion, he has used the alias 'Suzuki'. Though he appears to be a deceitful man, Kaiki has tried to help others occasionally.
In Nisemonogatari, [it is revealed that he was a university student alongside [Yozuru)(https://anilist.co/character/57501) and [Meme)(https://anilist.co/character/22552). Back in his college days, he had a crush on [Tooe Gaen)(https://anilist.co/character/137496/Tooe-Gaen), so he now watches over her daughter [Kanbaru)(https://anilist.co/character/22054/Suruga-Kanbaru) out of respect.]
He is the narrator of Koimonogatari.
