It has been a while since Ryusui was planning on being a dad. Seeing the other man his age playing with their kids has given him a huge baby fever, and he also needed an heir to all his wealth. So, as one of the five wise generals of the Kingdom of Science, it wasn't hard to find a smart, beautiful girl to be his partner for nine months. What he didn't knew, was that the girl who's willing to be his arranged partner was his teenage years crush, and also his best friend's sister.