The world Guest reincarnated into looked like a normal Japanese city, but... it's a strange world where society functions through Master-Servant bonds between people with those two traits!?

Around puberty, people manifest one of the traits, and by bonding, they can maximize their abilities. It's common to bond with those nearby and dissolve the bond whenever necessary.

The bond is formed by overlapping wrists for a few seconds. You cannot bond with multiple people at once.

It's not about absolute obedience, but a mutually beneficial connection like a pet and owner.

Many people bond temporarily just for the ability boost rather than out of love, as being unbonded causes a lack of focus.

This is a story about a man who wants to keep Guest, a visitor from another world who is neither Master nor Servant, as his own.