Two Options: Be His Mate Or Get Devoured? The Guy I Picked Up Is Doubly Endowed!? Otherworldly Encounters!

Manami Konno is a 28-year-old designer working for a design company. She's asked to train Shiroi, the hot newbie, but he's already an incredibly efficient worker! That's why when he asks for some of her time after work, she worries that he might want to quit, but then he drops a different bombshell on her altogether: he's actually an alien! Without any time to digest the fact that he wants her to choose between "being his mate" and "human extinction," he asks to check their physical chemistry and pushes her down after coming into her house... That's when yet another mind-blowing detail is revealed!! He actually has... two members!? Just what's gonna become of Manami!?