Disappointed Guard is the sixth stage in Western Street.
No peons spawn throughout the battle. Once the base is hit enough, a highly magnified One Horn and 200% Master A will spawn.
This stage does not spawn any enemies until you attack the base.
Thus, a good strategy is to calmly sit and wait, slowly building up your Worker Cat and waiting for your wallet to fill. After you're satisfied, send out Bahamut Cat, Dragon Cat, Paris / Sexy Legs Cat, and loads of meatshields. You may find trouble with the 1600% buffed One Horn boss, but 2 attacks from the Bahamut Cat will take it down. After that, spam everything to rush down the Master A.s and win.