They're university students. The girl beats up the guy and takes over the club room he was using for her own club. He swears he'll be back in one year to defeat her. He trains in the mountains and comes back buff, and he finds her full-term pregnant. They spar a little and he tells her she shouldn't try with her huge belly, then they bond a little and she invites him to have sex with her. ("What about your husband?" "He's nice and all, but he kinda neglects me sexually now…") So they fuck, and he promises to fight her again in another year. He trains in the mountains some more, comes back, and she's carrying her kid on her back, and she's still just as knocked up, but now on her second one. "Then we had lots more sex…"
Kind of rare to get a manga that focuses on a pregnant woman that doesn't degrade into NTR, or that depicts the woman as being abused, but all in all it seemed only so-so.