I can't tell if I like this idea or not. I suppose since it involves the making of sushi, I'll just have to give it a thumbs up. However, I don't think it's quite sushi-sushi, if you don't have to roll it up.
Usually sushi is formed in a bamboo mat covered with plastic wrap. You place the vinegared rice--with or without sugar--and fish in a sheet of nori, add some vegetables if you like, then roll it up. And there you have sushi. I'm not sure why you need a device for handling the same task. Except maybe that it just looks cool. Which it does.
Looks aside, Sushezi operation is pretty simple. Place your goodies inside the hinged case, clasp it shut and push the plunger. I don't know if I would ever use this to make sushi, but that wouldn't stop me from using it. For example, it looks to me like it would be able to make some sort of stuffed mashed potato creation rather easily.
In the end, I am won over. Besides the more adventurous among us who may try to make mashed-potato sushi, typical users can always wrap a sheet of seaweed around the extruded rice tube. With the art of sushi-wrapping safe, order is restored in the universe, and Sushezi looks to be welcome to the table.