Wax on, Wax off

[EmperorZetta]

There is a reason this is the rarest trophy in this otherwise simple and straightforward beat-em-up - as soon as you get to the bonus stage (not even finishing it), the game autosaves you on the level after it.

 

Once you get to the Leek Takoyaki boss fight, quit the game and back up your save to USB/PS+ cloud. The bonus stage is right after this fight and you'll be able to repeat it if you fail to hit every wooden dummy, which is highly likely since the timing is strict. The order that the dummies pop up does not change between attempts.