Mattsu, Yamma and Moburi - The Naval Treasure and Riddle Island

Mattsu, Yamma and Moburi: The Naval Treasure and Riddle Island was released in 2014 as an original net animation (ONA). The project emerged from a promotional initiative by the Japanese Ministry of Land, Infrastructure, Transport and Tourism, intended to educate the public—particularly younger demographics—about the significance of the nation's maritime infrastructure and the technological advancements in its naval industry.

The production utilized a whimsical, character-driven aesthetic to make complex logistical and engineering themes accessible. Designed as a lighthearted adventure, the animation follows three primary protagonists as they solve puzzles and navigate naval landscapes. While it remains a niche entry in the landscape of educational animation, it is recognized for its commitment to blending government-sponsored public service messaging with standard genre tropes of the mid-2010s Japanese web-based animation scene.