Ruyanpe was born to an Ainu mother and father, where the former disappeared shortly after their birth. Consequently, they were raised primarily by their Aunt (mother's sister) and father. Their father would give them the name Ruyanpe, as they greatly enjoyed playing and being outside in the rain. Following the annexation of Hokkaido and subsequent assimilation into Japanese society, Ruyanpe's father became acquainted with a Japanese merchant and would enter the workforce. Effectively, it was slavery. Over time, he would become increasingly gaunt, until Ruyanpe would discover him nearly frozen to death. Before he passed, he would give them the name "Hokuto Yukie", hoping that, should it come to it, they could present as Japanese and live an easier life. Being the last gift they would ever receive from their father, they accepted the name, but refused to cast away their heritage. Ruyanpe, too, would depart the village after carrying their father's body back, much in the same fashion their mother did 14 years ago.

Yukie would end up working for the same merchant their father did, waiting for their chance to get revenge for their father. An eventual fight between the two would occur, but Yukie would not end up succeeding, instead ending up with a grave wound to their back and shoulder, nearly severing multiple nerves. Fortunately, a female doctor would witness the scrabble and get Yukie immediate medical attention, essentially saving their arm and life. The aftermath would leave them with a shooting star shaped scar on their back, extending to their front clavicle.

After this injury, they were left unable to work (not that they particularly wanted to continue anyways). As such, they spent the next years of their life as a vagrant, earning money in whatever ways they could. During this time, Yukie developed a particularly nihilistic view of the world, not only due to the types of people they would encounter, but also because of how they were treated. They would toss aside any semblance of morality as long as it aided in their survival.

Around age 20, Yukie would board a ship they belived was heading for Shanghai. And although that wasn't quite the case, a new chapter of their life would still begin.

Enishi is the second-born of the Yukishiro family, to his father, a former retainer, and his mother, who would pass away shortly after his birth. As such, he would be raised largely by his older sister, Tomoe. He would grow up to be a somewhat spoiled boy, but was still a loving person. Tomoe's childhood friend, and eventual fiance, Akira, would be somewhat of an older brother figure to him, providing him with the semblance of a proper, loving family.

After becoming engaged, Akira would become a samurai guard for figures of the shogunate and end up in the thralls of the Bakumatsu. Akira would unfortunately be slain by the Ishin-shishi's Hitokiri Battosai. After receiving news of his death, Tomoe would seek revenge against his killer, however, her plans would be put on hold when she finds herself falling in love with him. Enishi would join the same group Tomoe did, and be sent to her and the Battosai's countryside home, calling her to action. After Tomoe tells Enishi to go back home, he begins wishing even more ill on the Battosai for causing Tomoe such pain and "tricking" her. When Tomoe accidentally falls victim to the Battosai's blade in an attempt to save his life, Enishi witnesses this, and views it as the cold-blooded murder of his dear sister. This moment would set his life on a decade and a half long plan for revenge.

Enishi would leave Japan, refusing to live in a country built by his sister's murderer. He would find himself in Shanghai, desperately trying to survive before being picked up by a wealthy family when he was on the verge of death. In order to repay their kind actions, Enishi would murder the entire family as he "couldn't stand the sight of a happy family". Using the family's wealth, he would study and work his way up the ladder of the Shanghai Mafia, allowing him access to everything he could possibly need to carry out his revenge on the Battosai.

At some point, he would come into the possession of a secret island that would act as a relay point between Shanghai and Japan to fund his revenge plot with weapons and to act as a hideout. One day, a stowaway ends up on this island, changing the course of his life.