Papa no Iu Koto o Kikinasai!

The story focuses on the 19-year-old student, Yuuta Segawa, who suddenly discovers that he must take care of 3 young girls. This is because his older sister and her husband are missing. So, he has to move in with Sora (a middle schooler), Miu (an elementary schooler), and Hina (a kindergartener) in an apartment.