In 3015, during the reign of Huanli, two nations, Donatia and Kouran, are locked in a battle for dominance that threatens to tear the world apart. Nil Kamui, a small island nation, has been devastated by this war, with both sides claiming victory over its lands and people. To make matters worse, the deity of Nil Kamui, the Red Dragon, has become possessed and is wreaking havoc on the island, burning villages and slaughtering innocent people.
Ibuki, a descendant of Nil Kamui's royal family, resides at an orphanage and refuses to take up his birthright as king. Despite his pacifist tendencies, Ibuki is reluctantly drawn into this conflict due to the chaos that threatens his homeland. Can he rise to the challenge and save Nil Kamui from destruction?
Chaos Dragon is based on the role-playing fiction project Red Dragon, a story which was created by five notable character designers: Gen Urobuchi (Fate/Zero), Kinoko Nasu (Kara no Kyoukai), Iduki Kougyoku (Mimizuku to Yoru no Ou), Ryohgo Narita (Durarara!!), and Simadoriru (member of the Stripe Pattern doujin circle). The results of their tabletop role-playing game sessions over six days created material for a seven-volume light novel series.