Leika Sugi is a Japanese creator known for co-developing the cyberpunk action franchise Ninja Slayer. Along with writing partner Yu Honda, Sugi is credited as one of the original authors of the series, which began as a serialized story on Twitter. While the initial premise presented the work as a translation of material by fictional American writers Bradley Bond and Philip Ninj@ Morzez, subsequent reporting and official publications identify Honda and Sugi as the authentic creators behind the property.

The Ninja Slayer story is set in the futuristic, dystopian metropolis of Neo-Saitama, where a vengeful spirit known as the Ninja Slayer wages war against cybernetic ninja clans. The franchise expanded from its Twitter origins into a series of novels published by Enterbrain beginning in September 2012, with illustrations by the artist Warainaku. Leika Sugi is specifically credited alongside Yu Honda for manga adaptation supervision on titles such as Ninja Slayer Kills, the manga adaptation of the original novels.

Beyond the core novels, the Ninja Slayer property has generated multiple manga series. Leika Sugi is credited as an original creator for these adaptations, including the manga Ninja Slayer and Ninja Slayer Kills. The franchise also received a twenty-six episode net anime adaptation produced by Studio Trigger, which premiered in April 2015.

In February 2021, it was announced that Leika Sugi and Yu Honda would collaborate with artist Jun Hanyunyū on a new manga series. Initially listed under a temporary title, the work was later confirmed as Arata no Kemono (Arata the Beast). The creators described the project as brutal paranormal pulp action entertainment, and it began serialization in Kadokawa's Comic Beam magazine on March 12, 2021. This project represents Sugi's major original work outside the Ninja Slayer universe.

The creative identity of Leika Sugi is closely tied to the elaborate backstory of the Ninja Slayer franchise. The fictional narrative of the series being translated from obscure American publications is now understood to be a conceptual framing device, with Sugi and Honda recognized as the genuine architects of the property. The recurring themes across their work involve hyper-violent action, supernatural or paranormal elements, and gritty futuristic settings. Leika Sugi holds significance in the manga industry as part of a creative team that successfully transitioned a grassroots Twitter serialization into a multi-platform media franchise encompassing novels, manga, and anime.