In the year 2010, the Japanese radio industry is in decline. To reverse their flagging ratings, a station staffed with perennial losers makes a daring gamble: to hire the industry's first android on-air host. Maico is cute, but it will take more than novelty to win over the fickle audience -- especially with a crew as inept as this one.

​On the island of Regalo, a group of supernaturally powered mafia-like protectors called the Arcana Famiglia safeguard the people from any who would harm them. The members of their organization, having made contracts with tarot cards, each possess different abilities, such as overwhelming strength, invisibility, or the power to see into someone's heart. Mondo, their leader and the "Papa" of their family, announces at his birthday party that he will be retiring soon. He plans to hold the Arcana Duello, a competition that, if won, will grant the winner the title of Papa and any wish they desire. But there is more at stake than just a title: Mondo also decides that the winner will marry his daughter, Felicità. Enraged by this, the strong-willed Felicità decides to enter the competition herself, in order to make her own way in the world. As Felicità battles for her freedom, her competitors battle for her heart.

After toiling away in his lab, the alchemist Jolly has finally succeeded in making a personality-swapping potion that is guaranteed to bring him entertainment. The boys of the Arcana Famiglia are tricked into taking the potion and find themselves in bodies that are not their own. With this successful experiment, Jolly has paved the way for a plethora of uncomfortable scenarios. However, despite the boys' desperate struggle to switch themselves back, there is something to be learned from spending the day in someone else's shoes.

In the wake of a third world war which left Japan in ruins, an organization known as Vischio seized control of Tokyo and renamed it Toshima. Taking place in its back alleys are battle games known as Igura, overseen by the Vischio, in which contestants battle and bathe in each other's blood to earn the chance to go up against its tournament's king, Il-re. Igura is not the only fighting tournament around; Bl@ster is a similar yet vastly different game since it prohibits murder and the use of weapons. The only way to win is by knocking out the opponent. Akira, a young man isolated from his family, is known to be undefeatable at Bl@ster. However, his life on the top is shattered when he is accused of murder. Unable to prove his own innocence, all hope is seemingly lost... that is until a mysterious woman named Emma appears and offers him a chance. Now, to regain his freedom, Akira must participate in Igura and ultimately defeat Il-re.