Okane Ariki No Kankei Desu Ga summary:

Half a year ago, Yanai Makoto, a normal office employee, became his friend’s guarantor for a large loan, but in the end the friend fled and left him with enormous debt of 30 million yen. Yanai became a call boy in order to pay off the debt, until one day he stumbled across a yakuza who claimed "love at first sight" and was willing to pay 5 times his price if Yanai became his personal whore…