Papa no Iu Koto o Kikinasai!

Yuuta Segawa has just begun his first semester in college. One day, his sister Yuri, who raised him after their parents passed away, requests him to watch for her three girls when she and her husband travel abroad on a business trip. Hina, Sora, and Miu are Hina's daughters. Yuuta reluctantly agrees, but disaster strikes when their jet vanishes and it is believed that every passenger is dead. Yuuta goes against their family's wishes and takes the three girls in, just like his sister did for him when he had no one else, in an effort to stop the three girls from being split up. The four are now in an unfamiliar and odd situation: Sora, Miu, and Hina are dealing with the death of their parents, while Yuuta is learning how to manage his new responsibilities as the newest member of the Street Observation Research Society, a people-watching group.