Akira Nishiguchi was born on December 14, 1925, in Osaka, Japan. He grew up in a family that valued their Catholic faith. His parents owned a fishing business on the Gotō Islands, which are located off the western coast of Kyūshū. As part of their religious beliefs, his father expected him to become a priest when he grew older.

To help prepare him for this path, Nishiguchi was sent to a Catholic mission school in Fukuoka Prefecture for his secondary education. However, he struggled with the strict rules and discipline at the school. He could not handle the pressure and decided to leave during his third year. After dropping out, he ran away from home.

In October 1963, Akira Nishiguchi committed his first murders. He approached Ikuo Murata, who worked for the Japan Tobacco and Salt Public Corporation. Nishiguchi offered to help Murata with deliveries. On October 18, they traveled to a remote area in Fukuoka Prefecture with Goro Mori, who was driving the car. There, Nishiguchi killed Murata with a hammer and stole ¥260,000 from him. He then turned on Mori, stabbing him before fleeing the scene.

After the murders, Nishiguchi celebrated by visiting a barbershop where his mistress worked. He showed off the money he had stolen. The next day, he learned through a newspaper that police were looking for him. Fearing arrest, he traveled to Karatsu, where he won more money at boat races. To confuse the police, he sent a letter to the Yukuhashi police, claiming he would commit suicide. He then boarded a ferry to Tokyo and discarded personal items overboard to make it look like he jumped from the ferry.

Nishiguchi moved around frequently, staying in different places. On October 28, he rented a room in Shizuoka while pretending to be a professor. The landlady, Yuki Fujimi, befriended him and eventually invited him to stay in her room. After staying for several nights, he killed Yuki and her mother, Harue Fujimi, by strangling them with a rope. He stole their cash and valuables before leaving the area.

Days later, he was in Chiba, where he tricked two women out of money, pretending to be a lawyer. He also stole money from a businessman and continued his fraudulent activities across various cities. His next victim was Umematsu Kamiyoshi, an 81-year-old lawyer. Nishiguchi posed as a lawyer, gained entry into Kamiyoshi's home, and strangled him with his necktie before robbing him.

On January 2, 1964, Nishiguchi approached Tairyu Furukawa, a Buddhist priest, under a false identity. However, Furukawa's daughter recognized him from a wanted poster. She alerted her family, and they took steps to protect themselves while informing the police. The police surrounded the Furukawa home quietly. Early on January 3, when Nishiguchi attempted to leave, he was arrested without resistance.

Following his capture, Nishiguchi confessed to the murders. He was put on trial and received the death penalty for his crimes. His appeals were unsuccessful, and he remained in prison until his execution by hanging on December 11, 1970.