The most visible sushi restaurant in Ashland is Kat Wok, and it is a wonderful place, but you have to be a Trust-Fund Beneficiary to eat there. For the same quality at about half the price (and none of the atmosphere) find "Bonsai Terikaki", 2305 Ashland Street. It is a pad location in a strip-mall with Albertson's. Short on ambience, everything is fresh, including bulgogi the last time I visited, and it has the added advantage that you can afford to feed your university student and 8 of her closest friends for less than your next paycheck.
Keywords: With teens, Japanese / Sushi, Restaurant, Everyone, Dinner, Moderate (US$ 11 - US$ 20), Korean