even though she fails are reconciling with her biological brother, she still denies rental brother's offer of continuing the rental service because she still wants to fix the situation with her own ability, and she's also aware that her renting another "brother" is actually severing her bond with her real brother. In response to that, rental big bro then says that if she won't rent him, then he'll rent her since he's actually been saving up all the money she gives him, and plans on using that money to "rent" her time so that he can still keep an eye on her and make sure she's safe (physically and emotionally) especially since she'll be tackling this tricky situation head on.