Death March to the Parallel World Rhapsody, Vol. 16 (light novel‪)‬

Showdown in Castle Town!
 
Having successfully averted the airship attack, Satou and company arrive safely in the royal capital. There, they are reunited with Nana’s “sisters”—Numbers 1 through 8—and give them the gift of a lifetime. But as is tradition with every trip to the capital, Satou must rub elbows with the aristocracy before he can enjoy his sightseeing. He even receives a surprise visit or two, including a summons from Sir Juleburg of the Eight Swordsman of Shiga! Because no leisurely trip would be complete without a friendly duel…