If you don't know, AKB48 is a pop group consisting of a large number of young girls performing catchy yet ultimately terrible J-Pop and they have a stupidly large following of rabid fans who are almost completely on the wrong side of obsessive. Personally I don't give too many shits about them, if you're drunk in karaoke then they are there to provide stupid songs that are easy to sing in Japanese but I'm not the kind of person to put them on by choice.
Anyway, this isn't the first game I've seen from them, they have some kind of dating sim looking thing which I THINK is called AKB 1/48 but that game kind of makes sense to me. The idea of being able to romance your favorite member of AKB must have been prime spanking material for the aforementioned rabid fans but the idea of a game where you shoot the group in the face strikes me as kind of odd.
I skipped almost every cut scene during my play through but from what I could tell there is some kind of zombie outbreak that has changed a bunch of the members into zombie and it is up to you, the player, to use your vaccine gun and un-zombie them. You are joined by the one remaining not zombied member who will give advice, get in the way, spout nonsense and help combat the outbreak with catchy pop music.
At the end of every stage you have to play a simple rhythm game where you use the guns triggers to hit notes to some of the most well known songs of the group. They are pretty easy and it's hard to fail but if you're playing 2 player then your partners fuck up can cost you health which is a little annoying. Then again, providing that you have a working brain these rhythm sections shouldn't pose any difficulty, it's overly simple and is more of an annoyance than anything else.
Anyway, just to round things off have a short video of some of the game play. It would have been a little longer but my wife, who was recording the footage, wanted to play so this is all you get.