I'm a Noble on the Brink of Ruin, So I Might as Well Try Mastering Magic Swimsuit Girls

This is from Episode 10 where Liam planned to collect salt and water to create an ocean, and his subordinates request help for Radon, who is the reason why there is no ocean. With Radon's assistance, a makeshift fake ocean was created in the Promised Land, which can clean itself after each use. Everyone then decides to play on the new beach, and Liam was embarrassed with having to judge the girls in their swimsuits.