I would recommend it. The outside area is open on weekends for more space. However they are moving to a newly constructed building on the other side of Arbys. As of now the space would be to small to just show up. Not sure if that will be the case when they move.
I've found that the staff at Ichiban is great at accommodating large parties when I've gone there with a group sontaneously. They have a lot of seating and the staff does everything they're able to do to make their customers happy. Obviously if you know you're going in advance, make a reservation.
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