@FacelessOne
I thought the illustrations looked familiar...
You copied the name of the illustrator incorrectly.
Kagachisaku per the cover, and KagachiSaku per their home page. kagachi_SK on Twitter, and かがちさく on Pixiv. MAL has them as Kagachi, Saku.

They do nice work.

This is up to volume 12 now.

https://pbs.twimg.com/media/ERSEG6wUEAE8MXL?format=jpg&name=large

Usami also graces the cover of the artist's new art book.

alt text

https://rimg.bookwalker.jp/1052963/6u1VY3UN~QyhkEGh4TxtSw__.jpg