Megumin thought Kazuma and Aqua were acting strangely to pay her back for writing on Kazuma's belly. If she apologized, they might just stop it already.
The flashbacks gave the audience the idea that they were indeed just messing with Megumin.
But no, they were play-acting at being nouveau riche because of Vanir's offer of millions to buy Kazuma's otherworldly consumer products.
Then suddenly, everyone was on a trip to a hot springs town, even taking Wiz with them. Aqua tried buffing her luck to beat Kazuma at rock, paper, scissors, but Kazuma has never lost that game. Not once in life. I have a feeling we're getting set up for something...
Of course, our crew will run into bad luck. This time, their caravan got attacked because some wild animals were attracted to Darkness' new adamantine armor. Darkness couldn't wait to get trampled.