This has been featured around the Innernet recently, so why not here? Personally, my biggest skepticism is that I suspect it actually needs a mix of dark soy sauce and a much lighter sauce that floats on top?
I dunno though, maybe the ‘trenches’ are so deep that it works with simple soy sauce? Pretty dang clever, either way.
In the spirit of Starship Troopers, if you’d like to know more:
https://www.boredpanda.com/dishes-sauce-images-appear-3d-print-japanese-redestu/
Also, I’d recommend tamari instead. I don’t think it’s as traditional for sushi, but it’s less salty and richer. It seems less likely to overpower the fish rather than complement it.
Ponzu ftw