Miss Kuroitsu From the Monster Development Department (2022)

S1E9 The Rotting but Heroic Figures of Ancient Souls of the Dead that Congregate in the Abyss Find a Ray of Hope in the Darkness from Pride Pulled from Another Time

Kuroitsu devises an innovative strategy to take down Blader in an underwater showdown! To assess the swimming abilities of her creatures, she organizes a series of classic beach competitions that will push their aquatic skills to the limit!