Since a thread in August 2001 (I'm a frequent lurker and infrequent poster), I've been meaning to try Oishii. While I've frequently contemplated the car-less trek from Porter Square to Chestnut Hill, I finally bit the bullet today. Oishii's accolades are well deserved.
Dining alone, I ordered three rolls (before tip, $29). My favorite came off of the "Customer's Specials" board -- it was called Amy's special. Basically, it was an eel and cucumber maki roll surrounded by slices of hamachi (like a rainbow roll), and then drizzled with ponzu sauce. The hamachi was wonderful -- almost buttery in texture -- and perfectly complemented a well executed eel maki. The ponzu sauce added an interesting undertone to the roll. This item was the big winner.
The second roll, the White Tiger Maki, was a tuna roll surrounded by white seaweed and sauce. I was drawn to it by the white seaweed which I have never experienced. Again, very tasty. The mayonaisse-based sauce drizzled over it seemed to dilute/overpower some of the other flavors, but no real complaints. The final roll was a soft-shell crab roll. The interesting aspect of this roll was the inclusion of tamago with the soft shell crab. A very solid interpretation, though I probably will skip it on subsequent visits (I'm from New Orleans originally, and tend to be a bit disappointed with the soft shell crabs I've found in Boston -- they tend to be smaller, and in my opinion less flavor packed, than those from the Gulf).
An exceptional part of the dining experience at this cozy restaurant was interacting with other diners. The modus operandi for ordering seemed to be looking down the sushi bar at what others had ordered, asking the names of the items that looked most appealing, and following the crowd. It was a fun experience, and is among the most natural dining alone experiences I've ever had.
I look forward to return visits. I'd love to try some of the more unusual offerings (baby hamachi, fatty tuna, etc.) during my next visit. In addition, on my way out, I heard a customer raving about the first item on the customer's special board (which I did not try and don't remember the exact name) -- it was a "shot" of sea urchin, quail egg, tabasco and soy sauce. In any case, thanks to the many members of the chowhound community that suggested this restaurant. Well worth the commute!