I can't lose them too... Not again. The following article contains significant spoilers and/or ending details of Valkyria Chronicles 4. If you don't want to get shot, tread carefully!
Squad E, to the Beach! is a downloadable content for Valkyria Chronicles 4, playable after clearing storyline Chapter 10. The DLC features two battle missions with five Aces who unlock swimsuits for Claude Wallace, Riley, Raz, Kai, and Minerva. They can be selected as alternate uniforms under the tab marked "seasonal auto-switch" on the soldier profile after they are unlocked.