I tried only a few Japanese restaurants and do not remember the names. So I googled Jpanese restaurants in Boston and here come some hits.
1280 Beacon St, Brookline, MA 02446 · 617-738-1268
16 Hudson St, Boston, MA 02111 · 617-338-2261
63-65 Galen St, Watertown, MA 02472 · 617-923-2100
I have seen this and looked expensive.
612 Hammond St., Chestnut Hill, MA 02467 · 617-277-7888
I went there with a seminar, vibrant speaker. We, four guys, ate about $140 in total. I like the food there and place; it is very tiny. They opened bigger one in South end and it seems very popular for gay people. I have never seen the types of sushi I ate there, but they taste really good. If we spend $140 we could have made good sushi from Yoshinoya food.
10 Huntington Ave, Westin Copley Place, Boston, MA 02116 · 617-266-2788
57 Broad St, Boston, MA 02109 · 617-542-4311
90 Peterborough St, Boston, MA 02215 · 617-536-6688
Village Sushi & Grill
14 Corinth St, Roslindale, MA 02131 · 617-363-7874
Some day I shall go there when I get rich but I am not so big fan of dine out. When I came to Boston for the first time I went to a Japanese restaurant; I was somewhat freaked out when a woman there spoke to me in Japanese since no one has ever spoken to me in Japanese in Canadian restaurants. Often they spoke to me in Korean.