Botsuraku Ojou-sama ~Chijoku no Ninshin Race~

The lead character is the son of a millionaire, recently receives an offer of marriage making with two well-off girls for the purpose of financial help to the girls' families.
One is a gentle, pretty girl, and the other is a cheeky girl who is a member of the school committee for discipline in school, seeing him as an enemy.

He tells them, have no choice but to obey him to save their families, to choose either of them as his fiance who is pregnant with his child before the other does......

[From DLsite English]