Okitegami Kyouko no Iromihon

The tenth instalment of the Boukyaku Tantei Series. The only employee of the Okitegami Detective Agency, Oyagiri Mamoru, receives a sudden threatening phone call. "If you want Okitegami Kyouko back, you'll have to come up with one billion yen." He is the only one who can rescue the lonely forgetful