After beating down powerful enemies of Gauron and Gates from the rival organization Amalgam, Jindai High School finally restored the peaceful daily life as usual. However, it didn’t last long……Misbehaved Amalgam officially starts to attack Sousuke Sagara and the others. The 'Mithril' bases of the world have been severely raided! The Merida Island, where Tuatha de Danaan lead by Tessa is sheltering, comes under attack by a large number of missiles and armslaves. Meanwhile, the Devil is also approaching Sousuke and Kaname in Japan! Sousuke, Kaname, Tessa and the others will be facing trials again!