Shojiro Nishimoto was born on October 22, 1976, in Iida, Japan. He came from a wealthy family. His father worked at a bento production company, and his mother was the daughter of the company president. Soon after Shojiro was born, his father had to go to Tokyo for a work assignment. This left Shojiro to be cared for by his mother.

On August 21, 1994, Shojiro transferred to Iida Hamaiba Elementary School. He seemed like an average student. However, he often skipped school because he felt he was not good at it. This pattern continued into junior high school. His school performance got worse, especially as his parents frequently argued and eventually divorced.

After finishing school, Shojiro found a job at a forest maintenance company. However, his coworkers viewed him as an unsatisfactory worker who did not put in much effort. When he was 21, he switched to a different company. In August 2002, he got into a car accident that caused a herniated disc. This injury forced him to retire from work.

Without a job and running low on money, Shojiro returned to Iida. There, he married a woman and told her he was the son of a famous entrepreneur. Despite marrying, he accumulated debts from rental companies and personal spending.

On January 13, 2004, Shojiro Nishimoto’s car ran out of gas while he was driving in Nagoya. Unable to find a bicycle to steal, he took a taxi to Kasugai. Once there, he murdered the driver, Yasuo Minato, who was 59 years old, and stole 18,000 yen from him.

On April 27, Nishimoto broke into the home of a 77-year-old woman named Mie Shimanaka in Iida. He strangled her and took 15,000 yen and a piggy bank. Her body was discovered later that same day by her daughter.

Nishimoto looked for another victim and found 69-year-old Hitoshi Kato, an unemployed pensioner. He entered Kato's home on August 10 and stabbed him in the chest, causing him to bleed to death. Nishimoto stole 260,000 yen from Kato's house. The police found Kato’s body four days later.

On September 7, Nishimoto went to the house of 74-year-old Aiko Kimura, whom he had previously burgled. He knocked on her door, apologized for the disturbance, and then stabbed her multiple times, resulting in her death. He took her wallet and a purse containing 6,000 yen before leaving. Kimura's daughter found her body later.

Nishimoto’s final crime occurred on September 13, when he tried to break into a house belonging to an acquaintance in Iida. He triggered an alarm, alerting the homeowner, who called the police. Nishimoto was arrested shortly after.

During interrogation, he confessed to the four murders. Nishimoto faced trial and was found guilty of the charges. On May 17, 2006, he was sentenced to death.

In October 2006, during his appeal trial, he confessed to another murder, claiming he had killed a woman in Fukushima in 2003. Police could not find her body, and Nishimoto later said his confession was a lie born from fear.

In January 2007, he dropped all his appeals, accepting his death sentence. On January 29, 2009, he was executed by hanging at the Tokyo Detention House, along with three other inmates.