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,

Spoiler

it is revealed that he was a university student alongside Yozuru and Meme. Back in his college days, he had a crush on Tooe Gaen, so he now watches over her daughter Kanbaru out of respect.

He is the narrator of Koimonogatari.