It may be unorthodox, but having seen both installments of Danganronpa 3 in tandem, I feel like it's best to review them as such. While they tell very different and independent stories, they work most effectively in parallel, with the tense action and whodunnit story of the Future Arc feeling ever more tense as the backstory of the Despair Arc chugs along, seemingly without incident. The Future Arc treads much more along the path of the original Danganronpa , with a mystery murder game in place between the leaders of the Future Foundation, who had managed to bring the world Hope in the midst of Despair years before (note that by the time of Danganronpa 3 , “hope” and “despair” have become immutable keywords to describe the forces of good and...evil I suppose).
Meanwhile, the Despair Arc is a prelude to the Future Arc 's grand despair, the humdrum high school the original Danganronpa flew in the face of, but with just as much of a sinister undercurrent. Interleaved together the episodes feel like a Memento-style suspense tale, complete with the same plot twist revealing itself at around the same time in both works.
There are few common characters between them aside from the administrators of the titular Hope's Peak School, namely the enigmatic chairman Tengan and the happy-go-lucky teacher Yukizome, as well as Future Foundation leaders such as the militant Munakata. Furthermore we hear the names of many of the students from the original Danganronpa , from the world's symbol of Hope, the idealistic Naegi, to Enoshima Junko, the source of all the world's Despair. Each plays a prominent role in one of the arcs and is completely absent from the other; it's as if each has claimed their own piece of the story, never to directly meet in battle again.
From the way the Future Arc introduces itself, with Naegi having sheltered a group of so-called “Remnants of Despair” who run counter to the Future Foundation's goal of Hope throughout the world, we know immediately that these Remnants are hidden in the Despair Arc , possibly even the group of students in Yukizome's class, the Hope's Peak High School's pride and joy. Soon Yukizome and Tengan, both still around for Future Arc , are left mute by a killing game wherein the Future Foundation leaders are trapped within their headquarters and forced to find who is killing them every night when they fall asleep. The two of them, along with Naegi, Munakata, and a few of the students from Danganronpa are all left to band together to escape the game, but through a combination of slightly canned dramatic dialogue and some more deft use of secrecy and banned actions, all of them are set at odds with one another, to the point where the mysterious nighttime killer barely does any of the work by the end.
The Despair Arc is a far different state of affairs. A class of super-specialized high school students come together as their new teacher Yukizome helps them learn how to get along, and to use their talents for the good of everyone. One students is a gamer, Nanami, who befriends a boy named Hinata from the lower class. Another is an animator, Mitarai, obsessed with making anime that brings Hope to all who see it. It becomes hard to see who and what will ultimately become relevant in this seemingly happy story, but we are told outright that the Despair Arc will eventually live up to its name, even if it seems the more Hopeful of the two.
In both stories, there is a side focus where the external members of the Future Foundation are investigating the rise of Despair. The Future Arc features Naegi's sister Komaru fighting along side a side character from the original series, Genocider X, as they try to find the mastermind behind the killing game. The Despair Arc is a bit harder to pin down; Yukizome is investigating the school on the side, trying to figure out what their secret Kamakura Project is. This actually feels more like the side to the side story, as it eventually loses its place to the arrival of the true elements of Despair, but it does lend credence to Yukizome's infiltration and the show's focus on her as a teacher within the school.
The threads all weave together in an elegant way, but to me the show's greatest discerning factor, the battle of Hope and Despair, also ends up being the factor that derails it. For all the talk of Hope and Despair, how they are opposites that give rise to one another and such, there seems to be little in the way of substance behind it all. They are only slightly more fleshed out than the more classic struggle of Good and Evil, that distinction being “Despair is fun!” This also seems to be enough of a justification for them to break out some lazier plot devices, and in particular they introduce a mechanic that eliminates all the credibility and suspense of both arcs, as well as the struggle between Hope and Despair altogether. While the character narratives themselves remain strong to the end, and the imagery only gets more and more striking as the show goes on, it begins to feel like Danganronpa 3 is more interested in doubling down on Danganronpa 's themes to build a cult following than keeping the integrity of their narrative afloat (edit: my sources tell me they've succeeded in the former count).