Long ago, a great war took place among ninjas in the country. The four surviving clans—Koga, Iga, Fuma, and Saika—maintained a fragile peace by each possessing a powerful item known as the Crypto Scroll, which ensured a balance of power. In the present day, the ninja city of Kouka (also referred to as Koka) has become an ordinary town where people have forgotten that ninjas ever existed. This peace is shattered when a Crypto Scroll enshrined in the city is stolen, igniting a battle royal among ninja clans who now vie for control of the artifact.

The story follows Sakuya, a young ninja from the Koga clan who would rather stand out than hide in the shadows. She lives a quiet, ordinary life in Kouka with her friends Nemu and Xiaolan, but the theft of the Crypto Scroll forces all three to set aside their peaceful routines. Uniting their skills, they are drawn into the escalating conflict and must fight to retrieve the scroll before the chaos spirals further out of control.

The series spans multiple seasons, with the first season premiering in October 2023, the second season following in January 2024, and the third season, subtitled San no Maki, airing from July to September 2025. Each episode runs approximately three to five minutes, delivering a fast-paced, compact narrative that blends action and comedy. The anime is produced by studio Fanworks, with Akifumi Nonaka directing and Toru Hosokawa handling the script. The original characters are based on the CryptoNinja NFT project, created by Ikehaya with illustrations by Rii2.