Sui Ishida was born on December 28, 1986, in Fukuoka Prefecture, Japan. As a child, he moved frequently due to his father's work, living in several Japanese cities including Tokushima, Tokyo, Kanagawa, and Saga, as well as spending time in Taiwan during his kindergarten years. He began drawing in first grade and developed an early desire for professional manga tools, though an incident where he spilled ink on a tatami mat led him to avoid using such equipment for a decade.

Ishida’s professional career as a manga artist began with his one-shot version of Tokyo Ghoul, which earned second place in the Weekly Young Jump 113th Grand Prix in 2010. The series was then serialized in Shueisha's Weekly Young Jump from 2011 to 2014 and collected into 14 volumes. The story, which follows Ken Kaneki, a college student who becomes a half-ghoul after an encounter with one, became a global phenomenon. It has been adapted into various formats, including novels, anime television series, and a live-action film. The manga topped The New York Times Best Seller list in 2015, and by 2021, the franchise had sold over 47 million copies.

Following the original series, Ishida expanded the universe with several works. He wrote and illustrated Tokyo Ghoul [Jack], a prequel serialized digitally in 2013, and the one-shot Tokyo Ghoul: Joker in 2014. The direct sequel, Tokyo Ghoul:re, was serialized in Weekly Young Jump from 2014 to 2018 and collected into 16 volumes. Regarding the anime adaptations, Ishida was credited as the creator of the original manga for the first season. For the second season, Tokyo Ghoul √A, he was additionally credited with the original story concept, indicating a more direct involvement in crafting the new narrative direction for the anime.

Ishida’s artistic identity is marked by a distinctive and experimental visual style. His artwork, particularly in Tokyo Ghoul:re, is noted for its sketch-like, ethereal quality and innovative panel layouts that push the conventions of the manga format. Thematically, his work frequently explores complex and dark subject matter. Academic analysis of Tokyo Ghoul has examined its narrative through the lenses of identity, medical ethics, and the psychological impact of bodily transformation, drawing parallels to literary works like Franz Kafka's The Metamorphosis. Ishida himself has stated that his personal definition of success is not tied to commercial performance or popularity, but to his own sense of accomplishment and whether he feels he has created something good. He has expressed that he does not consider Tokyo Ghoul a success by this personal standard.

Beyond the Tokyo Ghoul franchise, Ishida has contributed to other projects. In 2016, he drew a 69-page storyboard focusing on the past of the character Hisoka for Yoshihiro Togashi's Hunter × Hunter, which was published digitally. He is also the original creator and character designer for Jack Jeanne, a video game for the Nintendo Switch that blends visual novel and rhythm game elements, released in 2020. His current ongoing manga series, Choujin X, began serialization in Shueisha's Tonari no Young Jump in 2021.