Ore x Yome
Himekawa is 26-year-old and has a beautiful girlfriend who wants to remain a virgin until she's married. He's lied to her and told her that he has a career with a company when in fact he works at the local convenience store. Ashamed, and wishing to power up his career so he has a shot at actually marrying his girlfriend (and her virginity), Himekawa replies to a want ad and is surprised to get an immediate response.
Gyakushu no Ore x Yome
Kou's very good with computer science and robotics, but not very skilled with the opposite sex. He has a crush on his coworker, Moe, but he hardly even speaks to her. Then one day, his 99-year-old self from the future sends him back a present; an android of Moe that only wants to make him happy. His future self comes along for the ride, in the form of a little phallic robot. His new penis-bot and android girlfriend are definitely going to make his life a lot more complicated.