Rising of the Shield Hero Volume 17: the Manga Companion,

The only way for your own world to survive is to sacrifice another?! Naofumi and company head for the dragon hourglass with one of the four holy heroes of another world, Kizuna. But first, they need to earn some money - and they're going to do just that by putting on strange masks and starting an auction! But when they arrive at their destination, Naofumi begins to feel uneasy.