First, the title in Japanese: "Onii-chan Sen-you Delivery JKPlus -RJ01319065-". The key parts here are "Onii-chan" which usually refers to "big brother", "Sen-you" might be "senso" or "battle", "JK" is a common abbreviation for Japanese female high schools, so "JKPlus" likely refers to an adult version. The "RJ" prefix indicates it's a doujinshi (self-published work) with the specific ID number RJ01319065.