朋友把妹妹作为500日元的借款还给我、我该怎么办, I Lent 500 Yen to a Friend. His Sister Came to My House Instead of Borrowing. What Should I Do?, When I Lent 500 Yen to a Friend, He Sent His Sister as Collateral, but What Should I Do?, Saat Aku Meminjamkan 500 Yen pada Temanku, Ia Mengirimkan Adiknya sebagai Jaminan, tetapi Apa yang Mesti Aku Lakukan?, Cho bạn thân vay 500 yên, trả nợ bằng cách gửi em gái đến, rốt cuộc tôi phải làm gì đây?, Cho thằng bạn vay 500 yên nhưng hắn gửi em gái làm tài sản thế chấp, thế rốt cuộc tôi phải làm sao?
"Until my brother returns the 500 yen, I will gladly become senpai's property as collateral!" One summer day, Akari Miyamae, his friend's younger sister, came to the apartment of Motomu Shiragi, a university student. What is the secret behind this debt, and what is Akari's purpose...? An overly-sweet cohabitation comedy that starts with one coin!