The protagonist Lan Yu, who was transformed into a demon by a mysterious organization, came to his hometown of China with the two heroines in order to retrieve his memory. Unexpectedly, several other rebellious demons also smuggled themselves to China. In order to win over Lan Yu, they used inducements and threats, but Lan Yu ignored them at all and the two sides became estranged. The other mysterious organization asked Lan Yu for help to deal with the strange creature "Huan", but will Lan Yu help them?