In this "bad ending" conclusion to the story, Ryouta casts aside his history with Oda and, with it, his hesitation, as he squares off against his former friend and rival, who has taken Kaguya and Uesugi hostage. Meanwhile, Himiko and Kira hatch a plan to save their captured allies. But Ryouta's decision will have dire consequences for everyone involved, and even he might not emerge from this final battle unscathed...Who will be left standing as the curtain falls on this explosive drama?!

In a hell called the Sanctuary... When his plan to escape the island ends in failure, Ryouta drags his battered body ashore, only to be approached by a mysterious girl who leads him to a community of seven combatants managing to peacefully co-exist. With Ryouta's arrival, though, the balance is shattered as the eight chips needed to win a ticket back to civilization are suddenly within reach! It doesn't take long before the first death is discovered, and so a brand-new arc commences with an explosive tropical murder mystery!!

In this "happy ending" conclusion to the story, it's up to Ryouta to persuade Oda--who has taken Kaguya and Uesugi hostage--into believing there's no need to fight. Making his job harder, however, is Takanohashi, who fans the flames of their rivalry by declaring their duel a proxy war between the East and the West. Meanwhile, Perrier attempts to rescue the hostages, but approaching Uesugi only leads to disaster...The fate of the players and the destruction of the THEMIS Project hinges on Ryouta, but will his ideals be enough to make a happy ending reality?

A forbidden partnership forms?! "BTOOOM!" and its trademark bombs have decimated both the island playing field and players alike, but is the final stage of this live death-game now in sight?! Tsuneaki Iida, programmer for Tyrannos Japan, shares key information about the game's masterminds and the conspiracy, and he lets Ryouta in on a secret function hidden in the BIMs, asking him to take down the game's system. Still plagued with doubt, Ryouta steels himself for battle and carries out his do-or-die plan to hijack the Tyrannos Japan helicopter. There's no turning back now!! But the price Ryouta will pay for his operation is heavy...and an unexpected turn of events awaits!!

The Sanctuary arc comes to an end!! While lying unconscious on a beach, Ryouta is approached by a mysterious little girl, Kaguya, who later leads him to the Sanctuary, where seven "BTOOOM!" players have been eking out a peaceful coexistence. But Ryouta's arrival means there are enough chips to send one player home, and a string of ghastly murders follows!! The killer cuts down player after player, and Ryouta soon discovers that he has fallen into the villain's clutches, only to escape by the skin of his teeth! As the curtain falls on the battle of wits between Ryouta and the murderer, another rises on the most ferocious fight the Sanctuary has ever witnessed!!

Komaru and Toko delve into the subway tunnels, finding an underground arena where Masaru, leader of the killer kids who call themselves the Warriors of Hope, stands triumphant above a pile of dead grown-ups...yet the boy doesn't stand a chance against Genocide Jill and Komaru's teamwork! Now having defeated a foe, the question arises as to who's actually their friend...Shirokuma, a bleached, bandaged version of their teddy bear tormenter, claims to be able to put them in touch with the adult resistance--but is following it down even deeper really such a good idea? Based on one of the multiple video games in the Danganronpa franchise, Danganronpa Another Episode: Ultra Despair Girls is the missing story that goes between the original Danganronpa: The Animation manga, and the recently published manga series Danganronpa 2: Ultimate Luck and Hope and Despair.

The surviving players continue to struggle against one another in a desperate attempt to survive in the latest installment of BTOOOM!