Stopped by Nijiya Market in Mountain View earlier today and it is getting very very festive there. Might be worth checking the SF J-town location if you are closer (in case they stock the same items)
There were a lot of products on sale that are either in season during this time of year, or offered only during the new year period. Some highlights of different things I saw:
Kuromame - small container of the great black bean. Typically marinated in sake and sugar. There was a brown bean equivalent, but I have no idea what it is exactly.
Kazunoko - herring roe. Several different variations/packages available.
Dashimaki Tamago - literally as big as a swiss roll. In the refrigerated deli section. Good sized Japanese style omlette.
Yuzu marinated saba and kohada - the character that looked more like grapefruit in kanji fooled me at first on the package. It was actually yuzu (closer to a lemon). The fish also had some thinly sliced yuzu strips on it too.
Fresh salmon sashimi - nice dark orange red shade. Not sure where these are from, but they looked more like wild salmon than the farmed regular orange kind. Saw a lot of this.
Blue fin maguro toro - came to about $67 or so a pound. Good sized slabs
Blue fin maguro seared slices - in the deli section next to the mixed sashimi. If you have had Sushi Sam's o-toro tattaki, the package I picked up looked like that, minus the green onion, garlic, minced ginger, and ponzu. Me thinks this is a great substitute for home creativity ;-)
That's all I remember....do go check out your local Japanese supermarket if you can!