Zuino is a Japanese manga writer and story creator. The creator works under the pseudonym Zuino, which is the international transliteration of the Japanese writing ずいの. Zuino is established as a scenarist, or scriptwriter, for manga publications.

Zuino is best known as the original author of the manga series Zeikin de Katta Hon, which translates to Books Bought with Tax. This series, a seinen comedy manga, began serialization on Kodansha's YanMaga Web online platform on August 16, 2021. The story follows Kiichi Ishidaira, a juvenile delinquent who begins working at a library after discovering he had failed to return a book for ten years. For this series, Zuino provides the story while the illustrator is Kei Keiyama. The manga was later transferred to Kodansha's Weekly Young Magazine. As of early 2025, the series remains ongoing, with individual volumes, known as tankōbon, collected and released by Kodansha. An official fanbook for the series was released in May 2023, which included a conversation between Zuino and the series' illustrator about their creative process.

In early March 2026, it was announced that Books Bought with Tax would receive both an anime television adaptation and a live-action series adaptation. The live-action adaptation is scheduled to begin in the summer of 2026.

Beyond this debut work, Zuino created another manga series titled Self Portrait, which launched on May 20, 2024, in the magazine Monthly Young Magazine. For this series, Zuino collaborates with the artist Zashima. The story is described as a drama revolving around a group of girls engaged in a dangerous game. This series is noted as Zuino's second major work following Books Bought with Tax.