It looks like Yoshinobu Yamada has been time traveling in 1960s America and what he came back with was the expression “Never trust someone over 30.” Where other volumes of Cage of Eden have been remarkable (in a not-so-good way) for the useless and/or passive roles of the female characters, in these two books we see a different, and possibly just as off-putting, trend – the near total inability of any of the adult male characters to be good human beings once society's rules are unenforceable. While there are some possible pop psychological explanations for this – perhaps it is the same reason why new drivers are more likely to drive the speed limit while more experienced ones go ten miles above it? – it is still a strangely unbalanced portrayal of humanity and one that is hard to ignore, no matter how exciting the rest of the story is.

Of these two volumes, four is the stronger. Picking up where three left off, with Akira and Ohmori in the clutches of the seemingly malevolent Miina and her yakuza henchmen, the two decide to play along with the apparently sadistic little girl in order to discover what happened to Ohmori's sempai and fellow flight attendant Towa. The way that Akira and Ohmori cooperate despite their age difference and the brief amount of time they have known each other is well done, and if Miina forces Ohmori into a ludicrous fanservice outfit (who packed that thing, anyway?), it is easily overlooked as the two ferret out the truth. Unfortunately the truth comes with some other passengers who have taken up residence in the same general area, and here we see the same vicious, rapacious nature that Yamada first showed us with the students back in volume one. While it does play nicely into the true history of Miina and the missing Towa, it is a bit worrying how quickly Yamada has his adult males go screaming off the deep end. Would men forsaken by society really devolve this quickly? Even in Lord of the Flies it took longer for the boys to become complete savages. Fortunately the action is fast-paced enough, and Miina's backstory interesting enough, that in this case it can be forgiven, particularly when we move on to the main group reuniting and discovering another student floating unconscious in the river.

The introduction of class representative Yuki jumpstarts the intertwined story of Kohei and his group. Kohei, we know, has been systematically killing people since the crash, and Yamada provides, through the voice of the brilliant Mariya, a relatively plausible explanation for it. More grippingly, his madness seems to be infectious, and by the time Akira, Rion, and the others find him in a limestone labyrinth, the stakes have been elevated quite a bit. Kohei himself steals the scenes he participates in, with his vulnerabilities making him strangely sympathetic as well as plain old pathetic as he rejoins the boy he has always thought of as his savior. This section also sees the return of Yarei, although his name is perhaps better pronounced “deus ex machina.” Yarai comes in at the conclusion of the Kohei segment in volume five, and his presence, while helpful, is almost too much so. In summary, Yarai and the teacher he waltzed off with appear, help save people, plant an idea in Akira's head, and then rides off into the sunset again. It's a bit too convenient and contrived, rather like the large group of students and two male teachers Akira's gang runs into midway through the book. Under the teachers' guidance, the students are building a school-country, an idea that is worth a double take. This, coupled with the amoral behavior of yet more corrupt adult males, makes these few chapters less exciting than they could be, although their conclusion is promising. On the bright side, it is worth mentioning that the women are playing much more dominant roles, with Rion showing real initiative and prowess, particularly during the Kohei chapters. Ohmori, too, is displaying more gumption and less dependency on the boys, although she is still far from what might be called a strong character. Likewise the fanservice has been toned down for these two volumes – although panty shots are still around, they are less plentiful than previously and show slightly less detail and there are many fewer instances of women pressing their breasts together.

In terms of art, extinct creatures and backgrounds still provide a great deal of viewing pleasure. These volumes see the introduction of two creatures readers may be familiar with (sabre-toothed tigers and dire wolves) as well as an abundance of lesser known but still interesting animals. Men's scraggly facial hair is another artistic detail that is nicely done and as more students are added to the mix, most of them remain easily distinguished. The translation maintains its natural flow, although a few translations, presumably for the word “nakama,” feel a bit awkward, such as “peeps” and “compadres.”

Cage of Eden is still an exciting, engaging story of the struggle to maintain some sort of society in a harsh, unfamiliar environment. Volume five slips up a bit in our ability to buy into the story and Yamada's dim view of adults can be distracting, but with reduced fanservice and Rion's increasing competence, this remains a great escape into adventure for a few hours.