Masakatsu Nishikawa was born on January 14, 1956, in Tottori, Japan. He was the youngest of five children and the only son in his family. His father was a day laborer who did not pay much attention to his children. This led Nishikawa to live mostly with his mother. His sisters often left for the San’in region in winter to earn money for the struggling family.

In 1962, he started elementary school but did not go often because he was bullied. This bullying affected his ability to study well in school. At home, things were hard as well. His father was abusive towards his mother, and his mother was strict and often physically disciplined Nishikawa and his sisters. When Nishikawa was in third grade, his mother, who had diabetes and had been hospitalized multiple times, died.

In May 1970, when he was about 14 years old, he was sent to a childcare facility in Yonago for stealing. There, he learned to read and write. After he left the facility, he discovered that his father had sold the family home. This made life even harder for him as he now had to find work. He traveled to Kyoto and Osaka in search of jobs before returning to Tottori in October 1971.

After coming back to Tottori, one of his sisters took him in, but this situation did not last long. He was sent to a juvenile detention facility for committing several thefts. In October 1973, he was given temporary leave from the facility and worked with some relatives for a while. However, he soon quit that job and started to spend his time at pachinko parlors and movie theaters. During this period, he got involved with local delinquents, which led him to steal money and vandalize property.

Masakatsu Nishikawa began his series of crimes just a few weeks after being released from prison in late October 1991. His first known murder took place on the night of December 11, 1991, when he entered the "Kumi" snack bar in Himeji. There, he suffocated the 45-year-old owner, Kumiko Masaki, and stole 6,000 yen along with other valuables. He disposed of the murder weapon and Masaki's credit card as he traveled on a train, trying to cover his tracks.

On December 20, Nishikawa attacked Fumiko Takahashi, a 55-year-old snack bar hostess in Matsue. He strangled her and took about 200,000 yen in cash. After this murder, he fled the area, attempting to escape detection.

Two days later, on December 26, he entered another snack bar, "Maki," where he killed 55-year-old Kyo Harada. Nishikawa used a knife to slash her throat and robbed her of 5,000 yen before leaving her body in the bar.

His next victim was Noriko Murakami, a 51-year-old, whom he attacked on December 28 in the "Nakama" snack bar. After stabbing her and stealing 10,000 yen, he was confronted by her son. He hit the son with a beer bottle but fled the scene. Murakami later died at the hospital.

After these murders, Nishikawa became a fugitive. Law enforcement across multiple prefectures began to connect the dots, identifying him as the suspect in a series of similar snack bar hostess murders. He changed his appearance and continued to evade capture while committing additional thefts.

On January 5, 1992, he attacked Hanae Katsura, a famous comedian, attempting to murder her in her apartment while stealing money. However, she managed to escape with her life, leading to a renewed police effort to apprehend him.

Nishikawa was finally arrested on January 7, 1992, after staying with a woman who reported him to the police. He confessed to the murders. Over the following months, he faced multiple trials for his crimes. The evidence against him, including fingerprints and DNA matches, was significant. In 1995, he was sentenced to death for his actions and remained on death row until his execution in July 2017.