Also Harvest was the best doujin I could find about the series. There should be more.
There's the manga, which has 8 translated releases by Yen Press (who also did the LNs) ... which will never be scanned.
I love this page from the doujin.
Holo sure is a cute babe.
I always wondered how she'd get along with Amaterasu.
The art for them is actually quite good, I'd say they're easily worth the buy