Kinoko Nasu is a Japanese author, scenario writer, and co-founder of the creative studio Type-Moon. Born on November 28, 1973, he graduated from Hosei University with a major in human science. Nasu began his creative career writing novels, with his early work including the serialized novel Kara no Kyokai (The Garden of Sinners), which was originally released in 1998. Alongside his junior high school classmate and friend, illustrator Takashi Takeuchi, Nasu co-founded Type-Moon in 2000 as a doujin (self-publishing) circle. The group’s first major project was the visual novel Tsukihime, released in December 2000, which achieved significant popularity and established Nasu's reputation for unique storytelling. Following this success, Type-Moon transitioned into a commercial organization. Nasu wrote the studio’s next major visual novel, Fate/stay night, released in January 2004. The game became one of the most popular visual novels in Japan, spawning a vast multimedia franchise that includes numerous sequels, spin-offs, and adaptations.

As the primary creative force behind Type-Moon, Nasu has authored a wide range of original works. Beyond Fate/stay night and Tsukihime, his notable original creations include the light novel series Kara no Kyokai and the visual novel Mahōtsukai no Yoru (Witch on the Holy Night). Nasu has also been deeply involved in the development of numerous video games. He has written story dialogue and scenarios for the fighting game series Melty Blood, the role-playing games Fate/Extra and Fate/Extra CCC, and the action games Fate/Extella and Fate/Extella Link. Most significantly, Nasu has served as a primary writer and supervisor for the mobile game Fate/Grand Order since its launch in 2015, composing the storyline and dialogue for several of its main chapters, including the Sixth Singularity: Camelot, the Seventh Singularity: Babylonia, and the Final Singularity: Solomon.

The adaptation history of Nasu's works is extensive. The visual novel Tsukihime has been adapted into manga and anime series, while his novel series Kara no Kyokai was adapted into a successful series of anime films produced by Ufotable beginning in 2007. Fate/stay night has received multiple anime adaptations, including the series Fate/stay night (2006), Fate/stay night: Unlimited Blade Works (2014), and the film trilogy Fate/stay night: Heaven's Feel. The first film, Fate/stay night: Heaven's Feel II. lost butterfly, and the third, Fate/stay night: Heaven's Feel III. spring song, are among the specific works credited to Nasu as the original creator. Furthermore, the story chapters from Fate/Grand Order written by Nasu have been adapted into anime films and series. These include the film Fate/Grand Order The Movie Divine Realm of the Round Table: Camelot, the series Fate/Grand Order -Absolute Demonic Front: Babylonia-, and the film Fate/Grand Order Final Singularity - Grand Temple of Time: Solomon. Nasu has also worked directly on anime scripts, including serving as the original concept creator and series composition writer for Fate/Extra Last Encore.

Nasu’s artistic identity is characterized by several recurring themes and a distinct narrative style. His works often begin with a "boy meets girl" scenario and feature protagonists who live with internal contradictions or psychological burdens. The narratives frequently explore philosophical concepts related to morality, identity, the nature of humanity, and the boundaries between life and death. His writing is known for its dense prose, incorporating archaic language, specialized terminology, and lengthy descriptive passages. A defining feature of his body of work is the shared universe, often called the "Nasuverse" by fans, where different stories and characters coexist within a single, elaborate system of rules regarding magic, vampires, and heroic spirits. This vast and detailed world-building, influenced by creators like Mamoru Nagano, is a hallmark of his creative output.

Kinoko Nasu holds significant industry importance as one of the most prominent and influential visual novelists in Japan. The success of Fate/stay night transformed Type-Moon from a niche doujin circle into a major commercial entity, and the Fate franchise has become a global pop culture phenomenon, generating billions in revenue through games, anime, films, and merchandise. His work on Fate/Grand Order has been a major driver of the mobile gaming market in Japan. In recognition of his contributions, Nasu received the Tokyo Anime Award in 2018 for Best Original Script for his work on the Fate series. He also serves as the CEO of Notes Co., Ltd., the parent company of Type-Moon, overseeing the creative direction of one of Japan's most successful multimedia franchises.