Siiri Sampson 2011.It looks like grated parm, but something’s fishy about those translucent curls atop the roll. Good thing there wasn’t a sign saying “shaved salmon skin”–that would’ve totally ruined it.Everyone loves surprises–well, good surprises that is. Getting to the creamy center of an orange creamsicle, or making it to the heart of an artichoke for the first time after getting those sticky hair-like petals stuck all over your hands is worth the work. Occasionally you stumble upon an imposter dish like a cake disguised as a hamburger or a bowl of spaghetti–weird, but still good. And then there are the “so glad I had no idea” surprises, like you can find at IzaKaya Sushi in Renton (829 N. 10th St.).Anyone willing to publicly proclaim “I love sushi” has had enough nigiri, hand roll, or sashimi to figure out the pieces they toss back like candy versus those ingredients they avoid like, say, raw squid, large fish roe, or cream cheese. But sometimes curiosity gets the best of you, and next thing you know, a raw quail egg or monkfish liver shows up to the table. It’s not really a surprise since you know it’s coming, but the flavor, texture, and likability are still undetermined.Siiri Sampson 2011.The thing about shrimp tempura is that it’s always tasty and crispy, but you never know whether or not you’re supposed to eat the tail.Then there are gold, pink, and blue plates that whiz by on the conveyor belt at IzaKaya. Most have signs preceding them for the bulk of folks whose comprehension rarely ventures beyond the spicy tuna, California, or spider roll. Good on IzaKaya for preventing people from picking things they won’t eat or, worse, put back. As the train chugs past, a few straggler plates pass by every now and again with no sign. They’re snuggled up behind the tempura shrimp, but it’s obvious “one of these things is not like the others . . . ” Of course it’s too tempting not to grab, and it looks harmless enough with its veggies, rice, nori, and (maybe) meat. This mystery roll ($2.50 for 3 pieces) was smoky and salty like BBQ eel, but nearly too crunchy–more than soft-shell crab even–to be BBQ eel. Oddly enough, the roll was still really delicious. It had toasted sesame seeds and a thick, sweet sauce on top with the finest shavings of what looked like Parmesan cheese covering the top. After devouring all three pieces, the chef explained it was a crispy fried salmon-skin roll, which was good to know, albeit a little unappetizing. However, that still didn’t solve the mystery of the questionable (and flavorless) shavings, which turned out to be dried salmon skin shaved with a cheese grater. Somehow that was more off-putting than the large chunks of skin in the roll (think dandruff). And yet, the next time that roll came by, still without a sign, it was just as tempting as the first time.For all other train rolls, gyozas, and nigiri, it was decent quality for a decent price. The edamame was relatively fresh, and there wasn’t a single bad item to be had, save the fake cake. Fake cake is what sushi trains offer for dessert on the conveyor belt for the less adventurous. Usually fake cake is forgivable if they also offer a few quality, traditionally Asian items like deep-fried sesame balls. Unfortunately they didn’t have the prized sesame balls, so fake cake won by default. It was, as predicted, gross and a complete waste of calories. Luckily that was the only disappointment. The sushi parading by was better than that on most trains out there, and the bento boxes are generous enough to feed two. With a full bar and a nearby movie theater, there are still many meals to be had at IzaKaya.Follow Voracious on Twitter and Facebook.