As the new king, Sora and Shiro is entitled to live with luxury. However, they are not used to sleep in comfy bed and all other “royal” treatment, so they change their room back to their “old” style as hikikomori (shut-in) duo.
Meanwhile, Stephanie is handling day-to-day affairs of the kingdom, dealing with nobles who oppose the new king by limiting their authorities, all the good-and-difficult work of a ruler. Stephanie thinks Sora and Shiro don’t take their role seriously and trying to “set them straight” by challenging them into various games, multiple times. Of course, Sora and Shiro combo is unbeatable. So Stephanie is forced to walk with them to the city, wearing dog cosplay. With every subsequent loss, Shiro is taking one piece of her clothing.
Turns out, Sora and Shiro are not just randomly fooling around. While locking themselves up in their room, like doing no “work”, they have been reading all the books they can find in the castle. The secret of their winnings in games is that they learn about the strengths (and weaknesses) of their enemies. In this new world, they need to learn as much as they can about the other races they need to beat. Their “random” walk to the city turns out to be a search for libraries.
It’s interesting how Sora and Shiro explains to Stephanie that no game is actually about chance. Winner and loser of a game is already decided right at the beginning of a game. Indeed it’s one of the factors that makes this anime interesting.