We got there around 1:30, still a busy hour on a weekend, and sat down to wait; ten or fifteen minutes later, the spacy but sweet teenage hostess found us a table. Ono's interior is very much like a BBQ pavilion at an oceanside state park — the ones local families rent for birthday parties and whatnot — only enclosed. That gives a pleasant airy, beachy feel to the place, but also creates baffling acoustics; it isn't loud, but we could barely make out what our dining companion was saying from less than two feet away, and resorted to a lot of pointing, nodding and lip-reading.
SFist Lydia, contributing. Photo from Ono's site.