Kawasaki was destroyed by a giant monster that suddenly appeared. In a city abandoned by the government, the only person fighting the monsters is a yakuza who was based in Kawasaki.

Mafia Boss Genichirou Tokada Inukai, Asia's largest underworld organisation leader, completes 108 years of natural life. His inheritance going to his granddaughter totals to 5000 trillion ¥ (5 quadrillion yen or 46,560,140,000,000.00 USD), approximately 360 times the assets of the founder, roughly 17 times the national budget of Japan. Yet the desire of this unscrupulous daughter who has a non-standard financial power is to… make friends ? --- Alt synopsis: What do people want or do if they receive 5000 trillion yen all of a sudden? A youth comedy in the dark society. Chifuyu Inukai solves all things with the power of money, starting a comedy of unprecedented scale (of spending) in all history of manga.

A boy wakes up in a strange room and finds a girl passed out with him. They find out they both have weird collars on. The boy has a phone which seems to be connected to the people behind this. They want them to do what!?