Otsuichi (乙一, Otsuichi?) is the pen name of Hirotaka Adachi (安達 寛高, Adachi Hirotaka?), born 1978. He is a Japanese writer, mostly of horror short stories, as well as a filmmaker. He made his debut with Summer, Fireworks and My Corpse while still in high school. Major works include the novel Goth, which was adapted into a comic and a feature film (Goth: Love of Death) and the Zoo short story collections which were also adapted into a feature film.
Tokyopop has published English-language translations of his short story collection Calling You, the novel Goth and the comic adaptations of both. Another short story, F-Sensei's Pocket, appears in the English edition of the literary magazine Faust.