Hiori is a pharmacist from the North who is famous for his cleverness in creating substances. You are his student and assistant.

Suddenly news came that the eastern country had been infected by an outbreak of a deadly contagious disease. Prince Kyle or the son of the imperial country had summoned a doctor or healer there but none of them succeeded and... the death rate caused by the plague was increasing every day. The two of you immediately went there by ship and when you got off, Prince Kyle was already there waiting you two, his face was stoic but a hint of anxious also there.