Cardboard drones are now part of Japan’s military arsenal

Japan’s Defense Minister met with the team behind one of the country’s more unconventional defense startups — a company building military drones out of cardboard — and the conversation signals where Tokyo thinks its unmanned future is headed.

Shinjiro Koizumi, Japan’s Minister of Defense, held a meeting with representatives of Air Kamui, a startup that has made its name producing cardboard drones, and posted about the exchange on his official social media account. The Japan Maritime Self-Defense Force already uses Air Kamui’s drones as aerial targets — a confirmation that the platform has cleared at least the basic threshold of military utility and is operating in an active service role, however limited its current scope.

The cardboard construction that makes Air Kamui’s drones unusual is not a gimmick. Corrugated cardboard as a structural material for expendable aerial platforms carries genuine logic: it is cheap, lightweight, biodegradable, and fast to manufacture at scale. For target drone applications — where the aircraft is designed to be shot down — expensive composite airframes make no economic sense. A drone that costs a fraction of a conventional unmanned platform, can be produced in large quantities, and performs its mission adequately before being destroyed fits the target drone role well. The Maritime Self-Defense Force’s adoption of the platform for that purpose suggests the Japanese military has reached the same conclusion.

Koizumi used the meeting to articulate a broader ambition. He stated that Japan aims to become the Self-Defense Force that makes the most use of drones and other unmanned assets in the world — a goal that represents a significant statement of intent from a defense establishment that has historically moved cautiously on autonomous and unmanned systems. The Defense Minister’s direct engagement with a startup operating in this space underscores that the aspiration is not rhetorical. Strengthening ties with defense-oriented startups, Koizumi said, is essential to achieving it.

Japan is not simply talking about acquiring more drones — it is positioning itself to lead globally in the operational integration of unmanned assets across its military branches. That is a different and more demanding goal than procurement volume alone. It implies doctrine development, training pipeline construction, logistics and maintenance ecosystems, and the kind of iterative operational experience that only comes from actually using unmanned systems extensively in realistic conditions. Meeting with the companies building those systems — including small startups producing unconventional platforms — is part of building that ecosystem from the ground up.

Air Kamui’s position in the Japanese defense startup landscape is worth understanding. Japan’s defense industrial base has historically been dominated by large, established companies with deep ties to the government procurement system. The emergence of smaller, more agile startups pursuing novel approaches to military hardware reflects a deliberate policy shift in Tokyo — one aimed at injecting faster innovation cycles and a broader range of technical approaches into Japanese defense capability development. Air Kamui, with its cardboard drone concept that has already found a paying military customer in the Maritime Self-Defense Force, represents exactly the kind of company that policy is designed to support.

The target drone role the Maritime Self-Defense Force currently uses Air Kamui’s platforms for is operationally significant in its own right. Naval gunnery and missile defense training require realistic aerial targets — platforms that can simulate the speed, signature, and flight profiles of the threats ships must actually engage. Cheap, expendable, cardboard-constructed drones fill that role at a cost point that allows training to happen at higher frequency without the expense of recovering and refurbishing target aircraft. Every time a Maritime Self-Defense Force crew trains against an Air Kamui drone, they are building the proficiency that matters when the threat is real.

The broader context for Koizumi’s meeting with Air Kamui is Japan’s ongoing and accelerating defense buildup. Tokyo has committed to doubling defense spending as a share of GDP — a generational shift in Japanese security policy that is driving investment across every domain of military capability. Unmanned systems sit near the center of that investment priority, reflecting lessons absorbed from conflicts including the war in Ukraine, where drones have reshaped ground combat, and from the increasingly contested air and maritime environment in the Western Pacific. A Japan that deploys unmanned assets more extensively than any other military is a Japan that has fundamentally changed how it thinks about the defense of its territory and interests.