Sekai, an indie studio based in Paris and Tokyo, has launched "Naruto Ninja Cards," the first officially licensed digital card-collecting app for the "Naruto" anime franchise, in partnership with Japanese broadcaster TV Tokyo. The free-to-play app, released worldwide on Thursday, lets fans collect the series' characters as cards, unlock exclusive artwork and take part in real-time activities with friends, marking a rare case of the closely guarded IP being handed to an outside studio rather than kept in-house or licensed to a major publisher.

The project took five years to reach launch, beginning when Sekai's four-person founding team set out in 2021 to secure the rights, eventually spending 18 months in Japan persuading TV Tokyo to trust them, according to co-founder and CEO Samy Therain. TV Tokyo not only granted the licence but also invested in Sekai, its first Western investment since backing Crunchyroll; other investors include musician Mike Shinoda, NBA player Rudy Gobert and Alexis Ohanian's 776 fund. Since its soft launch on 5 February, the app has recorded 500,000 downloads, with Sekai saying 93% came from organic search.