volume 1: http://www.suruga-ya.jp/product/detail/ZHOA73557

In other doujinshis in e-hentai, Kanchuumimai is listed as a group (https://e-hentai.org/tag/group:kanchuumimai) and MK-O and/or Makuwa as the artist's name (https://e-hentai.org/tag/artist:mk-o and https://e-hentai.org/tag/artist:makuwa)

I'm using the information from suruga-ya, that seems to be correct. MK-O is the circle, Makuwa is the artist and Kanchumimai is the name of a series of doujinshis.

Listings showing MK-O as the circle: http://www.suruga-ya.jp/search?category=&search_word=&restrict[]=brand=MK-O and http://www.suruga-ya.jp/search?category=&search_word=&restrict[]=brand=MK%E2%80%90O

Kanchumimai as the doujinshi title: http://www.suruga-ya.jp/search?category=11&search_word=KANCHUMI+%E8%88%9E