Omae wo Onii-chan ni Shite Yarou ka!? (Light Novel)

One day, Yoichi who grew up while not knowing his parents has received the news of his father's death. His father left behind a testament——which said he is to pick only one out of five 'little sister candidates'?! The little sisters who were presented to him had more than one or two odd quirks, a slapstick comedy between siblings starts here!