They call themselves the Black Book Club: a consortium of billionaires who gained their wealth and power by dealing with evil demons. One of them has kidnapped a beautiful ice spirit named Yukina, tormenting her for the sake of her priceless crystal tears. Can the law-abiding entities of the Underworld tolerate this depravity? Of course not! That's why Yusuke, teenage delinquent and part-time Underworld Detective, has been dispatched to rescue Yukina and break up the Black Book Club.
Fighting alongside Yusuke is his friend and rival Kuwabara, who has fallen in love at first sight with Yukina. But if Kuwabara knew her family connections, he might not be so hot for the ice maiden. And Yukina's kidnapper isn't about to give her up without a fight. To destroy Yusuke and Kuwabara, he's hired nothing less than the Brokers of Darkness, demons so powerful that even the Underworld fears them. Yusuke and his friends are about to find themselves in the center of a demonic battle royale...
- Chapter 46 - Springtime for Kuwabara !!
- Chapter 47 - The Black Book Club!!
- Chapter 48 - Next Up: The Ogre Triad!!
- Chapter 49 - The Last Gamble!!
- Chapter 50 - The Final Battle: Two on Two!!
- Chapter 51 - I Must Get Stronger!!
- Chapter 52 - The Dark Tournament Begins!!
- Chapter 53 - The First Opponents!!
- Chapter 54 - The Vanguard Battle Begins!!
- Chapter 55 - The Secret of Devil Yo-Yos!!