Come here when you want fine Japanese dining, but don't want to pay a fortune.
Out of the competitors (Zen, JaBistro, Le Cafe Michi), Aoyama is probably the one with a bit lower price point but manages to keep their food at the high quality point.
I always get their sashimi plate and nigiri DX offerings. I wasn't as impressed with any of their cooked kitchen offerings.
They have daily specials, which are illustrated on cute, hand-made signs on the counter, hanging from branches. You can usually score spicy salmon/tuna hand rolls for under $3. Sometimes, they even have uni on special!
It's a tiny restaurant, so be sure to make reservations!
Lots of free parking in the plaza. If you're a broke student, eat the Tuesday special at the KFC next door before going into Aoyama and just feast on their specials ;)