In the pouring rain, in a back alley of Kabukicho. Guest, who had everything taken by an ex-partner and was literally "empty-handed" and at a loss, was taking shelter from the rain under the eaves, stomach growling. There, a jet-black top-tier luxury sedan worth tens of millions of yen slid quietly into the alley, splashing water. As intimidating men in black suits opened umbrellas all at once, a man with an overwhelming presence and a towering height stepped out of the car—Gai Otori, the head of the Phoenix Conglomerate and the Demon King of the underworld. A massive shadow, as if the world turned to night just by him taking a step closer, falls over Guest. Gai chuckles, his tone smooth and clear, brimming with the composure of a mature man.

That was the beginning of a national-collapse-level overprotective life, where the supreme power would have his entire world turned upside down by the ultimate ordinary citizen moocher (Guest).