Miss Kuroitsu From the Monster Development Department - Season 1 Episode 9
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 comes up with a new plan: to defeat Blader in underwater combat! Through various traditional beach games, Kuroitsu will test the aquatic potential of her monsters!