Born around 1845, Harada Kinu, later known as Yoarashi Okinu, lived through the transition from Japan's Edo period to the modernizing Meiji era. Her early origins are obscure, with contradictory stories in historical records. Some sources claimed she was the daughter of a samurai in Awa Province, while others suggest she was the child of a fisherman named Sajiro from Jōgashima Island. Still others speculated she was born in Edo (modern-day Tokyo).

What is known is that Kinu came from humble circumstances. According to the account of non-fiction writer Atsushi Hachisu, she entered the geisha profession due to poverty, and began working in Asakusa, the bustling entertainment district near Sensō-ji. Other accounts say she was once employed at a decorative collar shop in the Nakamise-dōri area. In any case, by the mid-19th century she had become known for her beauty and allure, attracting the attention of high-ranking men in Edo society.

Among those drawn to her was Ōkubo Tadayori, the daimyō of Karasuyama Domain, which held a stipend of 30,000 koku. Though she became his mistress and bore him a son, she was never formally accepted as a lawful wife. As the Meiji Restoration dismantled Japan’s feudal domains, Ōkubo, like many other aristocrats, sought to distance himself from concubines or associations that could threaten his social standing. He ultimately abandoned Okinu, separating her from their child and the Okubo family. This rejection marked a turning point in her life.

Okinu’s later years were marked by instability. She reportedly became involved with Kobayashi Kinpei, a man of lesser means. However, her attention turned to Arashi Rikaku, a popular kabuki actor with whom she became romantically obsessed. In an attempt to eliminate Kinpei and be with Rikaku, Okinu turned to poison.

On March 2, 1871, Yoarashi Okinu poisoned her lover Kobayashi Kinpei in order to pursue a relationship with the kabuki actor Arashi Rikaku, with whom she had become infatuated. Historical records suggest the murder was premeditated and motivated by emotional manipulation and desperation. Okinu acquired poison and administered it to Kinpei, causing his death.

After the murder, Rikaku harbored her, attempting to conceal her from authorities. However, their efforts were unsuccessful, and both were arrested shortly afterward. Okinu confessed to the crime. Her motives were linked to romantic obsession, financial instability, and possible emotional distress following her abandonment by the Okubo family. Her case drew intense public interest due to her former geisha status and her connection to high society.

While Rikaku was found guilty of aiding and harboring a criminal, he was sentenced to three years in prison and released in September 1874, later resuming his acting career under the name Ichikawa Gonjūrō. Okinu, however, received the death penalty. She was executed by decapitation on March 28, 1872, after giving birth to a child by Rikaku while in custody.

In the years that followed, her story was transformed into legend, especially through the publication of the 1878 book Night-Storm Okinu: Flower-Frail Dreams of Revenge, which cast her as a serial killer and femme fatale, though only one murder was ever confirmed. Researchers, including art historian Naoyuki Kinoshita, have since argued that much of Okinu’s posthumous reputation was shaped by sensationalism and fictionalization.

In reality, there is no evidence that Okinu was a serial killer, nor was there historical confirmation of multiple killings. Her case reflects the social tensions of the Meiji Restoration, including the fall of the samurai class, the fragile position of women like geisha in rapidly changing society, and the merging of media, folklore, and criminal justice.