Is the manga in Episode 3 of "The Everyday Tales of a Cat God" based off a real manga? In episode 3 there is a manga about a girl who moves to Tokyo after a string of bad luck only to find that her roommate is a death god who seems to just mooch off her. I am wondering if this is based off of another manga.







You can find more examples in the link in the comments. I think that's a large enough sample to determine if the manga used in the anime is based off any other manga.
кяαzєя's comment is right on the spot: Yes, it's from 大凶ちゃんとしあわせな世界 (Daikyo-chan to Shiawase na Sekai, Misfortune Girl and the Lucky World), a 2-chapter special spiritual one-shot by FLIPFLOPs on Champion RED magazine edition 2007-12 ~ 2008-01. It's also included in the 1st volume of The Everyday Tales of Cat God manga (Source:
MyAnimeList).


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The story, as it has been mentioned in the question, is about

Kyouko, a test-taker who came to Tokyo and is living alone.
Shinigami Karin, Kyouko's roommate.
The story about their certain Sunday life.
Source (Japanese)


Here, we can see Shamo reading the RED magazine,


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And here is the scanned page of the last picture in the question,


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