Yū Saitō is a Japanese manga artist best known as the creator of the romantic comedy series Giji Harem, also known as Pseudo Harem. Saitō both wrote and illustrated the series, which began as a webcomic posted on Twitter, starting on June 20, 2018, and concluding on March 5, 2021. Due to its popularity, the series was subsequently picked up for parallel serialization in Shogakukan’s Monthly Shōnen Sunday magazine, where it ran from January 12, 2019, to March 12, 2021. The complete manga was collected into six tankōbon volumes, released between March 2019 and April 2021.

The success of Giji Harem led to a television anime adaptation. The production was announced in April 2023 and was produced by the animation studio Nomad. The anime series aired from July to September 2024. Prior to this work, Saitō had also created another comedy manga titled Getsuyoubi wa 2-gen kara.

Giji Harem, Saitō’s most prominent work, is characterized by its short, self-contained chapters that depict the daily interactions between two drama club members. The narrative centers on the female lead, Rin, who uses her acting skills to portray a variety of character archetypes to please her senior, Eiji, creating a "pseudo-harem" from a single person. This premise highlights a recurring focus on nuanced character interactions and expressive facial acting over complex plots. The series' artistic identity relies on clear visual cues to distinguish the different roles Rin plays, allowing the reader to immediately grasp the dynamic of each scene.

In terms of industry significance, Giji Harem was recognized early in its run, receiving a nomination for the fifth Next Manga Awards in 2019 in the print category, where it placed seventh among fifty nominees. The work’s trajectory from a social media webcomic to a full serialized manga and then to an anime adaptation exemplifies a modern path to success for original creators in the industry.