A King of 1K

Due to having to pay the debts of a lover who disappeared Shiki is destined to living in poverty. One night, he discovered a man who had collapsed at the park and since he was worried about him he took him home with him. The collapsed man ended up being Tenma, the extremely famous top model!! Tenma quickly hands the debt collector a large sum of money in front of a surprised Shiki and tells him "Provide service with that body that I bought!!" and moved into the 1K (1 room + Kitchen) apartment where they started living together. Why is such a famous person living in my apartment!? Despite being bewilderd Shiki looks after Tenma!?