So, one TL thing, the all-girls group is "Yamato Nadeshiko." It's basically "The ideal Japanese Woman." And the male group is literally just... "Biceps."
Otherwise, it would be the Biceps Brachii, which is, uhhh... The longer medical name for Biceps.
EDIT: Honestly, using the term would not be 100% out of place. A bit awkward, because they want to be catchy meatheads, but that specific type of meathead knows the name of every single muscle group in their body, and is proud of this fact.