In Yokosuka, 1986, Ryo Hazuki, the only legitimate heir of the Hazuki Dojo, spends his days training under his strict father Iwao. One day, he returns and witnesses a mysterious man called Lan Di attacking the Dojo.
Hazuki Family's maid Ine hands a letter to Ryo, who is restless from his Father's death. The letter was sent from a person named "Yuanda Zhu" to his father which contained characters he cannot read.
