I became classmate with my mother in another world

Haruto Sato, 19 years old and a first-year university student, had finished his part-time job and was having dinner with his mother, older sister, younger sister, and aunt. At that moment, a magic circle suddenly appears on the floor, and he is summoned to another world. Suddenly, he is transported to another world, where humans and monsters are at war. The Sato family was summoned as their saviors by the royal family that governs the humans. However, there is something that confuses Haruto even more than that. That is... ``Haru-kun! It's like I've rejuvenated when I was a high school girl!'' My family, including my mother, has become younger and everyone is now a student. And the magical ability that I acquired when I was summoned said that I could strengthen the opponent's abilities by performing sexual acts with them ... ...................................................................... additional tag: incest ...................................................................... update:- 4-6 ch/week