Karin Hanazono is an ordinary 13-year-old girl who becomes depressed after the death of her parents and her last companion, her pet cat Shii-chan.

With poor grades, a mean aunt, and few friends who understand her, she feels lonely and desperately believes that God will help her out of these circumstances one day, holding on to the last remaining memento: a ring that originally belonged to her mother.

After Kazune returns from his trip to England, Karin and the others travel through time with a celebrity named Jin Kuga.

Koge-Donbo admits in volume one at how the point of Karin's "I am God" featured her say something stupid and the manga started was as a gag.

According to Koge-Donbo, Kamichama Karin was originally going to be a two-chapter one-shot manga, but she continued the story due to its unexpected popularity.

One night at her cat's grave, a young boy named Kazune Kujō approaches her, but she gets angry at him when he calls her a moron, punching him in the face for it.