Six months have passed since the end of the battle against the evil spirits. At Ryo's 16th birthday party, he and Nasty witness a news report about the Halo Armor committing random murders in New York. Sensing that something terrible is happening, Ryo heads to New York alone!

In order to rescue Seiji, Nasty, and Jun, who have been captured by a new enemy, the Shikaisen, Ryo, along with Luna, a local girl whose brother was killed in the incident, heads to the Japanese town where the Shikaisen awaits, along with Shin and Shu... But who is the enemy waiting for them there?! Now, the legend of the armor is reborn!