Tachimi tickets?

I have heard about standing room (tachimi) tickets being available in some theatres and Sumo events. Is it just a small selection of theatres which do tachimi? Does anyone know how you can find out if a theatre does tachimi tichets?
Thank you!

It usually depends on the event you are going to see. Some events are and some aren't, even if held at the same venue. If you look up the event info., 立見 (tachimi) will be written if there is a standing area.

I do not think there are many theatres which allow "tachimi". It really depends on the theatre and performance, maybe you can name those you're interested?

At least Kabuki Theatre (Kabuki-za) in Tokyo offers "hitomaku-mi" (meaning "seeing one act") which includes "tachimi".
Tickets for hitomaku mi is available only on the venue, on the day of the performance. You cannot make any reservation or buy hitomakumi tickets in advance.
They have both seats and standing for hitomaku-mi.

You are allowed to stand in a lot of theaters. What kind of theaters do you have in mind? Major cinema complexes don't allow standing while most small rock'n'roll clubs are all-standing. In any case, it's best to ask the organize or the show, as it also depends on the show rather than the theater.