Non reserved seats at Kabukiza

I'd like to go see a Kabuki play while in Tokyo this summer, and I'm interested in cheap non-reserved seats, but I've heard that for a play at 11am, (tickets booth opening at 10:30am) you have to queue up really early in the morning in order to assure having a seat?
I'm not really going to japan to spend my morning queueing-up in the street, so how does it really work?
thanks!

I suppose you are talking about the one-stage tickets on the day, sold at 600 or 1000 yen or so. For very popular performances, there seem to be queues at times, but depending on the day, you can just go soon before the ticket office opening time and it should be OK. You might want to phone (get your hotel concierge to call them up in the morning or the day before, maybe?) to ask them how popular the performance on the specific day you plan to go is expected to be.

What I know is that summer performances (some ghost stories that are easier to follow in terms of story lines) are quite popular.

We queued up an hour before it started and we were second in line, so we had seats. But I think it very much depends on the popularity of the show. The staff at the kabukiza were very helpful in explaining how it works and which show was suitable for 'gaijin'. You can get an english audio-guide which explains what happens during the show (recommended). The non-reserved seats are all the way in the back, so you might want to bring binoculars.

Thank you both for these answers!
I'll check beforehand what show is in august on their website, and i'll try to go on a weekday, when there hopefully are less people...
Do you think the morning show is less crowded than the evening one?