It is an animation made by Song Zhiyang's original works and light novels illustrated by なかじまゆか.

The hero, Sekawa Sukeyoshi, was originally an ordinary college student. My sister, who raised her since childhood, fell in love with Makoto Takahashi Wu, an old man with two daughters, married him and gave birth to a child. Deeply-rooted elder sister controls (I call myself)-Segawa Yuuta feels depressed and reduces contact with his elder sister. However, due to an aviation accident, Mr. and Mrs. takanashi were confirmed dead. At this time, Segawa Yuuta took Gao Naxi's three sisters home without hesitation and became their father! ? Happy, lively and touching family comedy

I hope my answer can help you.