An S-Rank Female Insect Wants Me to Pretend to Be Her Boyfriend

Set in a fictional alternate world and unrelated to reality. Please don't compare it to real life. Everyone in Meili's unit knew he had a childhood sweetheart, a male Zerg he'd grown up with. They'd heard his rank was low and he was sickly, but he made up for it with an incredible eye for investments. He'd even secured an S-rank female Zerg as his partner early on. An S-rank female Zerg! Bound to a sickly man. All the female Zerg officers at the camp felt sorry for Meili! Only later did they discover that the youngest and most handsome S-rank researcher in the research division was Meili's low-ranking fiance from a poor planet... Seriously, Meili, who do you think you're fooling?! Theme: Think twice before you act