During the initial attack of the Black Cross Army against the Japanese EAGLE bases, Jade Mask attacked the Hokkaido branch, killing everyone with Peggy Matsuyama the only survivor of the attack.
Disguising himself as an esteemed scientist, Jade Mask uses a lab to develop the "Jade Mold", a deadly mold that kills anyone who becomes infected by it, including through breathing it through the air. When two scientists try to defect from the operation, one is killed instantly while he infects the other with the mold as a warning to EAGLE. This scientist is discovered by Peggy, who disguises herself as a woman's magazine reporter to discover more about the mold and to stop the scheme. Ultimately Peggy is captured but discovers Jade Mask's delivery system, filling up a balloon with air filled with Jade Mold spores that will distribute through the atmosphere when it explodes. Midorenger prepares to destroy the balloon unknowing of this trick before Momorenger warns him not to, instead allowing Aorenger to capture the balloon with Variblune to spoil the scheme. Jade Mask tries to escape in a balloon of his own before being killed by the Gorenger Storm.