Tsukimichi - Volume 11 (Light Novel‪)‬

As every country slowly began to recover from the chaos sparked by the mutant incident, Makoto found himself constantly summoned by the Empire's nobles and the Kingdom's lords, running himself ragged through endless rounds of formal greetings.
Amid this whirlwind of obligations, he finally gave his answer to a long-standing proposal: a face-to-face meeting with none other than the Demon King. Invited to the demon capital-a land no hyuman had ever set foot in-Makoto was received with the personal hospitality of the Demon King himself.
For a mere merchant, such treatment was nothing short of extraordinary¿ leaving Makoto utterly at a loss for how to handle it!?