While simultaneously dealing with the scheming Inner Circle and the dangerous U-Men, the X-Men discover a disease affecting mutants' second stage of mutation - an anomaly that strangely appears to only affect mutants living in Japan.
Set after the death of Jean Grey, who succumbed to the powers of the Dark Phoenix due to the influence of the Hellfire Club's Inner Circle, the plot centers around Professor X reuniting the X-Men to rescue the young mutant Armor from the organ-harvesting U-Men. The series ran for a total of twelve episodes and prominently featured superpowered mutants Cyclops, Wolverine, Storm and Beast. The X-Men anime originally premiered in 2011.