The clones fight--some successfully, some not--to survive an attack on their school during their skills exhibition and are confused and frightened to find those trying to kill them are earlier generations of clones like themselves.
This is a rough volume in that a few of the people you've gotten to know through earlier volumes don't make it out the other side. And of those left, not all of them are stable (Hitler!) or adjusting well as they try to understand what's happened and why. The next volume promises to explain at least a part of that when the mysterious Kai, one of supposedly non-clone Shiro's older lookalikes, reveals what little he knows of his own story. I want to know, too! And then the kids need to kick their school director's soulless backside until he recognizes their equal humanity.