Ariyoshi vs. Pacific East
Be mindful that for my Japanese food, I only care about tempura and rolls.
Atmosphere: TIE
Pacific East is much smaller and more cramped. Their furniture is old, bordering wobbly. It was almost full when I went.
Ariyoshi is much larger, but it was almost empty the two times I went. The extremely good waiter to customer ratio is haunted by awkward silence. You also save couple quarters, since you pay the meters to go to Pacific East.
Tempura: TIE
While I enjoy tempura, I don't think I'm good enough to differentiate the subtleties. Both restaurants gave similar portion of crispy tempuras, coupled with the delicious sauce that I can't identify.
Rolls: Ariyoshi
It's been several months since I went to Pacific East, but I remember not being impressed; it was whatever. Then I tried Thai rolls in Ariyoshi, and DAMN they were awesome. I tried two other rolls there as well, and they were great. But the Thai rolls! THAI ROLLS!
Bottom line:
If you are fan of rolls, go try the Thai rolls.
If you haven't had too much exposure to Japanese food, try my favorite dinner: mixed tempura for appetizer and Thai rolls for entree. Order Sapporo if you like beer.