When Enishi was just an infant, his mother passed away, leaving him to be raised by his older sister, Tomoe. She took on the roles of both sister and mother, and their bond grew strong as Enishi came to love her deeply.
Tomoe eventually became engaged to Kiyosato Akira, and although Enishi was initially reluctant, he accepted Kiyosato because he made Tomoe genuinely happy. Hoping to become a hero for Tomoe, Kiyosato joined the Mimawarigumi, but he was tragically killed by Hitokiri Battōsai (Himura Kenshin) in the name of the new era. Heartbroken, Tomoe left Enishi behind to seek revenge, collaborating with spies from the Shogunate. Enishi, consumed by loneliness, longed to bring her back to Edo (now Tokyo) so they could reunite.
At around ten years old, Enishi ran away from Edo and disappeared for seven months. Through the Shogun agency, he found Tomoe and revealed himself as their contact. Although he believed he was aiding her quest for revenge, he was unaware that Tomoe had developed feelings for Kenshin despite his role in Kiyosato's death. She sent Enishi away to protect Kenshin, leaving him confused and angry.
After witnessing Kenshin accidentally kill Tomoe, Enishi's hair turned snow white due to the overwhelming stress and grief. His mental state deteriorated, and he swore Jinchū (Man's Punishment) against Kenshin for destroying his sister's happiness and ultimately causing her death. He fled to China, where he was taken in by a kind and wealthy family after enduring months of hardship. However, unable to bear their happiness, he murdered them and stole their money.
In 1878, now a powerful overlord in the Chinese underworld, Enishi returned to Japan, nearly forgetting how to speak Japanese. He then launched his Jinchu campaign with his "comrades."
