Yūichi Sasamoto is a Japanese science fiction writer born on February 18, 1963. He is recognized as a pioneer in the light novel format, a style of young adult novel often illustrated in an anime or manga aesthetic. Sasamoto himself has referred to his career as that of the oldest active light novelist. His debut work, Yosei Sakusen, was released in 1984 and is considered an early example of the light novel genre.

Sasamoto is best known as the author of the long-running science fiction novel series ARIEL. The series, which ran from 1986 to 2006, is a comedic mecha story about schoolgirls who pilot a giant robot to defend Earth from alien invaders. The title ARIEL is an acronym for "All-Round Intercept and Escort Lady." This novel series was adapted into two original video animation (OVA) series. The first, simply titled ARIEL, was released in 1989, followed by ARIEL Deluxe in 1991. Sasamoto was involved in the screenwriting for these OVA adaptations.

Sasamoto is also the creator of the light novel series Miniskirt Space Pirates, which began publication in 2008. The series follows Marika Kato, a high school girl who discovers she is the heir to a spaceship and must become the captain of a legally sanctioned pirate vessel. This series was adapted into a popular anime television series in 2012. The anime was titled Bodacious Space Pirates, as the original title's reference to miniskirts was deemed unsuitable for broadcast. Sasamoto is credited as the original author of the series. The anime was later followed by a theatrical film, Bodacious Space Pirates The Movie: Abyss of Hyperspace, which was released in 2014.

Beyond his original novel series, Sasamoto has contributed to other anime projects as a screenwriter. He co-wrote the screenplay for the 1989 animated science fiction film Venus Wars, working alongside director Yoshikazu Yasuhiko. He also wrote an episode for the Dirty Pair OVA series in 1987.

Sasamoto is a highly decorated writer in the field of Japanese science fiction. He is a multiple recipient of the Seiun Award, a prestigious honor for science fiction works. He won the award for Best Japanese Novel for Suisei Gari in 1999 and again for ARIEL in 2005. He also won in the Non-Fiction category for three consecutive volumes of Passport to the Universe in 2003, 2004, and 2007. The anime adaptation of his work, Bodacious Space Pirates, also won a Seiun Award for Best Dramatic Presentation in 2013. In addition to his writing, Sasamoto is known to be a rocket enthusiast and has been involved in a group of science fiction authors and artists who have pursued amateur rocket launches.