A lot rests on the shoulders of the kyukkies now. Sure, Reina can handle just about any lead, but MM isn't based around a lead singer, always at least two to four take important lines. Sayu has actually improved a lot as a singer, and as a well known personality, she can contribute a lot to the group. Aika has a fine voice, but she still needs to recover from her leg injury.
But Kyukkies now will be expected to carry a lot of the main singing parts
Can't help but feel they must have taken Risa's announcement pretty hard, if they did not already know about it. They obviously were treated very well by Ai and they loved Ai, but Risa was the one who hosted all those shows with the kyukkies, and if there is a mother hen to those girls, it has to be Risa.
Anyway, here is a concert rip posted by YouLookLovelyToday on YouTube, not sure how long it will last. Kyukkies definitely coming along well, and am sure they will be up to the challenge!