Sushi time? I went to a famous sushi restaurant you order by a tablet. It was so gooood!!
Authentic sushi restaurants won't serve salad or vegetable sushi except the cucumber rolls called kappa-maki.
If you'd like to have avocado rolls there are served at some Kaiten-zushi (sushi go-around) at Asakusa.
These already had soy sauce on them already, oh, but if you'd had to put on yourself, put it on the fish side, not the rice.
Soaking the rice could spoil the sushi. Bon appetit!!