While My Parents Were Suddenly Away... I Was Left with My Childhood Friend, and We Didn't Have Any Money for Condoms, So We Spent Our Days Creampie Fucking Like Crazy

In the plot, Hajime and Rei are friends, both living in the same building, both coming from very humble backgrounds, and both with broken families having just single parents, a Mom and a Dad, that eventually get together in an affair. However one day...