I'll try to keep this short lol it's a convoluted setup in words (spoilers!)
You should see a passage leading out of an impossible wall and think, "how do I get up there?" That's where the sushi is. Go to the bottom of the level with the two guards. You should be able to bring one with you by positioning yourself on the button. Position the guard on the side of the impossible wall, and stand on top of it. Get the other bottom guard out of sight so it doesn't get in the way. Jump as Edna, then quickly switch to the guard and jump, then switch back to Edna and jump off the guard. You should clear the wall this way. The game will ask you to do it again later, but it's much more obvious.
Also if anyone has a clip of them doing this trick with two guards (i.e. triple jump) PLEASE show me I have been trying for half an hour