I fly Y almost exclusively and lot of it is on NH's 773 (which I think is the equipment on NRT-SFO - I may be wrong).

The best seats in the house (at least on the wrong side of the curtain) is aisle seats 41C and 41H. I don't like window aisles (A,K) because of the bump(?) protuding from the exit doors limit leg space dramatically. However, not sure if NH is generous in giving these spaces out but I almost always am sitting in them. Another nice thing about the aisle rows is that it's close but not that close to the lavs (there is the galley in between your seat and then the lavs) so you can quickly spot if one is available instead of waiting. Since the galley is so close, the best time to hit the lavs in during meal service: take your tray and leave it in the galley. You won't be impeded by the cart service either. I know this sounds silly for those fortunate to travel in C and higher all the time, but here in steerage you find your own joys.

If aisle rows are not available, then the next best is rows 28-30. (Beware there may be babies and bassinet in row 27-noisy!). These rows mean you can deplane faster. Choose the middle aisle so you access to the aisles is easy e.g D,E. There is a video thing at the footrest of D but it doesn't bother me, feet still fit sideways. Some prefer bulkhead seating but I don't - the wall in fron of you limits your legspace.

Heaven forbid you get row 55 like I did once. Smaller and claustrophobic! NH bumped me from my preferred seating right to the back of the bus (despite my Plat status) because I checked-in 40 minutes before departure.

At the end of the day, it's just Y. Just take Ambien, one last emptying visit to the restroom, tell the FAs you don't want to be disturbed and sleep all the way like I do and then any seat is fine.