My opinion is there is no regulation. But these are the best places to watch beautiful kimonos so you might be watched.
The homongi wearers you may see at the entrance of the theater are kabuki actors' wives. So you don't need to wear like them if you are not a wife of a kabuki actor.
|Koshiro's wife and Somegoro's wife|
|Danjuro's wife and Ebizo's wife|