It's been clear that the anime adaptation of School-Live! differed from its source material for a while now, and two of these three volumes continue to make that evident – books four and five were covered at the end of the anime with some significant changes, while volume six picks up after the girls have left the school, probably for good. While both versions are powerful in their own ways, the manga begins to explore the idea of what people do in a crisis situation more fully, taking motherly Yuuri, better known as Rii, into greater consideration and paying more attention to how aware Yuki really is of their situation.

Volume four opens with Kurumi returning from her latest expedition, where she encountered what remains of Megu-nee, the teacher who initially survived for a while after the zombie outbreak. Because she had so many interactions with human Megu-nee, she's unable to defend herself against the zombie version, and Kurumi is bitten. She asks Rii to kill her, but by this point, the girls have found the emergency manual that the school prepared for teachers, and Miki steps up to the plate – since she didn't know Megu-nee, she knows that if anyone is going to be able to kill the former teacher and find the supplies, it's her. This is a major moment of character development for her, because when we initially met Miki, she was alone in a mall, afraid to leave the safe space that she and her friend Kei (who did leave) had created for themselves. That Miki is not just willing to put her life on the line, but to do so for her companions, shows us how much she's grown as a character, as well as how much better her coping skills have become.

By contrast, Rii is losing it fast. Kurumi's injury is ultimately what pushes her over the edge, but it seems possible that the knowledge that a cure exists and was readily available when the entire disaster started also led to her near-breakdown. With Kurumi's worsening state, Rii's grip on sanity begins to slip away, and watching (and hearing) her friend's transformation is perhaps more traumatic than the knowledge that this is what happened to everyone else she knew. It's around this point that she reveals she had a little sister, Ruu, and we can see that she's largely been treating the other girls as she would have Ruu; Kurumi's near-transformation brings home the fact that the same thing might have happened to someone she cared deeply for.

Rii's mental breakdown is shown in stages, making it different from Yuki's blanket denial of reality. At first, she simply mentions asking Megu-nee questions, not as if she's playing along with Yuki's delusion, but as if she actually believes that their teacher is alive and present. As she progresses, she grows obsessed with searching for Ruu, and when the girls have left the school and encounter a child zombie wearing a sign that indicates survivors at a nearby elementary school, Rii becomes adamant that they go looking for survivors to the point where she puts her own life in serious danger. While she does succeed in rescuing a lone girl from the school, there are small hints in the artwork and the other girls' reactions to suggest that this girl may be no more real than Megu-nee was – Rii has truly snapped, and now it's Kurumi, Miki, and even Yuki who must play along with her.

Taking the girls out of the school makes a bit more sense in the manga than in its animated adaptation. It's far more evident in volumes five and six that there are more survivors than the story first assumes, and their flight from their sanctuary is precipitated by a fire one of them causes. This evidence of other survivors, some of whom we see succumb to the zombie plague just after our hopes are raised, makes the story feel more urgent and also calls our attention to Kurumi, who may not have been as cured by the medication as we'd like. (The fact that she no longer feels cold and that full zombies don't appear to notice her presence could be some alarming foreshadowing.) This also allows us to see that Yuki may not be as far gone as her friends believe – at this point, her “delusion” could be more of a security blanket than a true belief, as we can see from her increased awareness of her surroundings and her ability to function as the navigator when the girls leave campus in a car.

These three volumes really show the series' strengths – its understanding and exploration of its characters' psyches as they try to function in a radically altered world and the sad reality that there may not be a way to set things right again. With each failed meeting, we can feel their sadness and with each reveal that this disaster was clearly anticipated by a large group of people, there's a burst of anger. It feels likely that the zombies were brought about by human tampering, as we see the documents Megu-nee had; in volume four, there's a reference to “strains still in development”, and the fact that even a few private residences have zombie-proof shelters definitely speaks to a group of people in the know. The foolishness that allowed this to come to pass is maddening, and Rii is likely on the verge of expressing that anger, especially if something happens to her “sister” or Kurumi.

School-Live!'s mix of cute girl moe and zombie survival horror continues to make it a stand-out of both genres, and these three compulsively readable volumes are hard to put down. With Kurumi's state uncertain, Rii losing her mind quickly, and Miki and Yuki stepping up in surprising ways as the girls take on the outside world, the series continues to build and develop. With such good zombie offerings as I am a Hero also available, I hesitate to tell you to read just one – but if you are a zombie survival fan, you'd be remiss not to check this series out.