One day for AKB, one day for SKE, one day for NMB...
More info in
http://stage48.net/wiki/index.php/AK...ippon_Budoukan
AKB concerts are usually concerts with aaaaaaaaaaaall the groups in it. While the sister groups have their own concerts and tours on their own, AKB has to share mostly everything cause they're the mothership.
That's why the Budokan series was so well received, it was the first time in years that AKB had a concert that they could call AKB-only. And the same is happening in March with the Olympic Stadium (while the sister groups will perform at Saitama Super Arena), which will probably be Yuko's graduation.