[Polyrhythm]

AKB48 is the original 48 group produced by Akimoto Yasushi (a famous record producer I guess...although I never heard of him prior to akb lol). They started out as an idol group of like 20 or something. Basically, just one team, Team A. They had shows like every day or something at their own theater in Akihabara (hence the "Idols you can meet" concept is brought to life). They were kind of a flop at first. I heard like 8 people showed up to their first show or something. Anyway, they added Team K at some point and then Team B. Each Team had a "Stage" they performed, or like a setlist of songs specific to the team (even though Team K debuted with Team A's first stage...hmm wonder how that worked). So that's basically what this "theater thing" is all about. They just have shows at the AKB48 theater every day.

SDN48 is a sister group of AKB48 that debuted with a more adult image. They were supposed to only perform on Saturday Nights at the AKB theater (thus the name Saturday Night 48) but I guess they outgrew that. Like SKE48 before them, they also got their own CD debut and all that jazz.

SKE48 and AKB48 are two completely separate (although similar) groups. They have their own AKB48 style theater in Nagoya. Anyway, they're supposed to be more young and energetic but they're basically the same. You probably got confused cause Akimoto basically used the Matsui's Jurina and Rena to promote AKB48 singles.

Then recently, a group of even younger girls (LOL) was formed with their own theater based in Namba. NMB48 just got their first CD debut, not unlike SKE48 and SDN48 before them.

Finally, there's a Hakata group, HKT48 that we pretty much know very little about at this point. I think they just finished selecting members or something.

Of course, the theater thing is the original concept. Meet your idols. Today of course, we're probably more familiar with these groups as being CD selling machines.