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. Ryo begins investigating the letter to find out his Father's past. As he further investigates, he is targeted by "Mad Angels", the gang that runs Yokosuka Harbor's underground business.
I don't know. But this thread is tied
to my father's mysterious past.
.لا أعلم. لكنّ هذا الخيط متصل بماضي والدي الغامض
Das weiß ich nicht. Aber mir scheint, dass ich der
Vergangenheit meines Vaters nachgehen muss, …
No lo sé, pero tiene
que ver con su pasado.
No lo sé, pero tiene
algo que ver con su pasado.
Je l’ignore,
Non saprei, ma voglio ripercorrere
 il passato sconosciuto di mio padre.
Não sei dizer. Mas quero saber sobre o 
mistério que é o passado do meu pai.
Не знаю.