Boxing Clever (Expert) is the first stage in Box Cats Awaken!.
Heavy Assault C.A.T. is outranged by Crazed Bahamut Cat but will be able to hit almost everything closer, so spam plenty of meatshields to keep Bahamut safe from the black enemies while you chip away at the boss. Ururun Cat also helps greatly in managing the wave of enemies and keeping them pinned at the base. Use Paris Cats to keep the enemies away from Bahamut (and Ururun if you brought her) when he's not attacking.
Crazed Sexy Legs Cat can easily handle the never-ending Crocos with wave attacks. You can spawn a few meatshields and a Cooldown Cat early on in the stage to max your wallet, but don't send in too many cats or you'll summon the boss before you're ready.