The Hiro Naval Arsenal (Hiro Kaigun Kōshō or Dai-Jūichi Kaigun Kōkū-shō (11th Naval Arsenal), often abbreviated as Hiroshō) at Kure (呉), Hiroshima prefecture, was a production facility for seaplanes, flying boats, and aero engines for the Imperial Japanese Navy before and during World War II. It was largely destroyed in a raid by B-29 Superfortresses on 5 May 1945.

Aircraft

Designed and produced:

• Hiro G2H - long-range bomber
• Hiro H1H - biplane flying boat developed from the Felixstowe F.5
• Hiro H2H - biplane flying boat developed from the Supermarine Southampton II
• Hiro H4H - flying boat

Prototypes and experimental aircraft:

• Hiro R-3 - flying boat, 1 example built
• Hiro H3H1 - flying boat, 1 example built
• Hiro H10H - project only, never completed^{[citation needed]}

Aircraft designed by other manufacturers produced at Hiro:

• Yokosuka B3Y
• Nakajima B5N "Kate"
• Aichi E13A "Jake"
• Yokosuka D4Y "Judy"

Engines

• Hiro Type 14
• Hiro Type 61
• Hiro Type 91
• Hiro Type 94