X-Men, still grieving over the death of Phoenix (Jean Grey), are investigating a case of a missing mutant girl in Northern Japan. This leads them to a mysterious virus that turns mutants into monsters. U-Men and the Inner Circle want it.
Cast: Steve Blum, Cam Clarke, Aya Hisakawa, Katsunosuke Hori, Rikiya Koyama, Toshiyuki Morikawa, Danielle Nicolet, Scott Porter, Stephanie Sheh, Yukari Tamura, Hideyuki Tanaka, Fred Tatasciore, Ali Hillis, Kaori Yamagata, Travis Willingham, Gwendoline Yeo, Troy Baker, Jennifer Hale, Haruhiko Jô, Michael Sinterniklaas, Dave Wittenberg
On the brink of world destruction, Charles reaches out to all the X-Men, other mutants and heroes around the world asking them to support one another and protect humanity.
Professor X summons the X-Men to protect humanity as the world is on the brink of destruction.
Marsh traps Emma Frost, Hisako and Yui; Neuron subdues Wolverine and Beast; Hisako reflects on a mutant who went into hiding.
The X-Men best Hedgehog and follow Marsh and Mastermind deeper into Yui's laboratory.
The X-Men battle a giant monster that turns out to be a transformed research assistant.
The X-Men return to Japan to probe the site where mysterious secondary mutations have occurred.
Emma Frost joins the X-Men; Hisako begins training; Professor X probes Emma Frost's mind to explore her past.
Professor X runs tests on Emma Frost out of concern for her safety after learning that the mutants that were captured by the U-Men are forming secondary powers.
The X-Men learn of a second mutant kidnapping, and they step into the trap of an anti-mutant group.
Professor X summons the team to reassemble to rescue a fellow mutant in Japan in the opener of the anime series following the adventures of a group of superheroes.