Gakuen de Jikan yo Tomare

The scion of an affluent nobleman is consumed by vengeance after being forsaken by his father and mother. Resolute on exacting retribution, he targets what his father values most: his twin daughters. Enrolling in their esteemed academy, our protagonist wields a bewitched temporal stasis device, courtesy of a powerful enchantress. With each encounter, he forcibly impregnates his unsuspecting half-sisters, reducing them to bewildered, desperate supplicants.