Sundeome!! Milkyway 3 (Young Jump Comics)

[Machine Translation] A secret mission between Yoshitake, an "S" type company employee, and Rene, an "M" type alien! Yoshitake has started a normal relationship with Haruka Yuien, a junior employee at his company, while Rene, a beautiful alien girl who came to earth only to make a baby with him, is left out. They go on trips to the beach together with Mika, a senior at work, and go on dates after work... and the intimacy grows day by day. However, this backfires and the feared situation arises!

“S”系会社員・義武と“M”系宇宙人・ルネの秘密の任務！自分と子作りをするためだけに地球にやってきた美少女宇宙人・ルネを差し置いて、会社の後輩・由井園遥と普通に付き合い始めた義武。会社の先輩・ミカさんも誘って4人で海に旅行に行ったり、会社帰りに2人でデートしたり…と日に日に親密さを増していく。だが、それが裏目に出て、恐れていた事態が！？