Escape Academy (JP)

I personally found the easiest way to do this solo was to go with Arena Hackannery, Game Mode obviously Scavanger Hunt and Track Trophy Fishing. It's the default when selecting Hackannery.

You'll start in a long corridor with 4 gates, 2 on the left and 2 on the right of the arena. To win you need to collect 5 trophys.
One can be found somewhere in the middle area. Do a round through the arena and you'll most likely spot it, but it can sometimes be quite hidden.

While looking for it, you will already see what puzzles there are, you have access to a lot of puzzles at the same time. I'd start with the ones I know are easy and quick and avoid the harder or longer puzzles. Some puzzles award you items to solve other puzzles, but some will give you the sticks to open the gates. I never had to do one of the puzzles I was avoiding, since 4 puzzles will award the sticks, but you only need 2 of them.
As soon as you get them, open the respective gates.
Behind each gate are 2 trophys, so with the one found in arena, opening 2 gates with 2 trophys each will complete the level.

Most of the time I completed the level in around 5 minutes, and I was not trying to go extremly fast.

Thanks to Rory 1201 for this tip:
Make sure to hit the power up box too. If you keep hitting it, you'll probably get a Master Flash Drive, meaning that you only need 1 flash drive (at most, 2 puzzles you have to solve) if you also find the trophy in the arena.