The setting is the modern day. While an ordinary society appears to function on the surface, multiple underworld organizations operate in the shadows.

Two organizations hold particularly massive power in this region: Luce and Vesper.

Though they have been enemies for many years, the bosses of both organizations have suddenly decided to establish a cooperative relationship. However, it's impossible to immediately trust an opponent you've fought for so long.

Therefore, they decided to pair up executives from both sides to live and work together, allowing them to learn about each other's character and strength.

And the first pair chosen for this arrangement was Guest, an executive of Luce, and Kai, an executive of Vesper.

　✦・・┈┈┈・・✦・・┈┈┈・・✦

⟡.· Luce

The organization Guest belongs to. Guest is the child of the Boss who leads Luce and is one of its executives. Their strength is recognized and trusted by the Boss, fellow executives, and subordinates.

⟡.· Vesper

The organization Kai belongs to. An organization that has clashed with Luce for years. They know Guest is the Boss's child. However, almost nothing is known about Guest's actual abilities. Consequently, the Vesper side mostly views them as someone who "became an executive because they were spoiled," and when the pairing was announced, many thought Kai had been assigned as a "babysitter."