Shoichiro Okubo was born as Masaichiro Okubo in Fukui City in the Fukui Prefecture in Japan. Okubo has a number of credits to his name as a screenwriter for live-action television series. He has also written screenplays for anime series and films.

For his anime scredits, Okubo is probably best known for writing the screenplay for the 1991 OVA of Mermaid Forest, which is based on the manga by Rumiko Takahashi. In this intense story, it is said in legends that eating the flesh of a mermaid can bestow immortality. But mermaid's flesh will affect people differently, and actions taken by one character end up affecting the lives of three others. This production includes graphic depictions of sex, drug use, and bloodshed.

Okubo also wrote scripts for the second Lupin III anime series that ran on Japanese television from 1977 to 1980. This series, which follows the comedic adventures and action of Arsene Lupin III and his partners in crime, ran for 155 episodes. In addition, Okuba wrote scripts for the Ninja Hattori-kun television anime series (which ran on Japanese television from 1981 to 1987). This series features ninjas, action, and comedy. The series ran for 694 episodes.

Okubo has also written scripts for anime films. He wrote the script for the 1979 anime film, Ganbare!! Tabuchi-kun!!, which is a comedic baseball piece. Okubo also wrote the 1982 anime film, Tsushimamaru: Sayonara Okinawa. This film is a historical piece based on the story of a Japanese freighter called the Tsushima Maru, which fled from Okinawa on August 22, 1944. The ship's cargo was mainly evacuees. The ship was struck by torpedoes from an American submarine off of Akuseki Island, sank, and took the lives of many of the evacuees.

Okubo wrote the screenplay for the live-action period drama Mito Komon. The series started airing in 1969, and has aired over 1000 episodes; Mito Komon is the longest running Japanese TV drama in history. In addition, he also wrote scripts for the Hana no Arashi and the Shabon Tama live-action television series. In 1997, Okuba wrote the screenplay for the 1997 mystery television movie, Asami Mitsuhiko shirizu 4: Tsuwano satsujin jiken.

Sadly, Shoichiro Okubo passed away in a Tokyo hospital on February 11, 2011 at 4:30 p.m. He died at the age of 63. Some sources have reported that Okubo apparently died from a stroke, but it is not officially known what he passed away from. Okubo is survived by his wife, Masaki Okubo.