Omae wo Oniichan ni Shite Yarou ka!?

Omae wo Oniichan ni Shite Yarou ka!?

お前をお兄ちゃんにしてやろうか！？

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'?!

"...I don't want to work, I want to laze around together with Onii-chan." (By Serene)

"Let's have a match! If I win, Nii-chan will... make me his little sister!" (By Tomomi)

"Onii-sama will choose me, isn't that right? It's our destiny." (By Sayuri)

"To be more girly, that's why I want to be Nii-san's little sister!" (By Yuuki)

"If Mii-chan becomes Nii-chama's little sister, she will become rich right?" (By Mika)

The little sisters who were presented to him had more than one or two odd quirks, a slapstick comedy between siblings starts here!