Designed and built by the Hiro Naval Arsenal, it was a twin-engined biplane that was operated by the Imperial Japanese Navy.

In 1929, the Imperial Japanese Navy purchased a single example of the British Supermarine Southampton II metal-hulled flying boat,[1] and, after evaluation, it was passed onto the Hiro Naval Arsenal (who designed the wooden Hiro H1H flying boat based on the Felixstowe F.5) to study its advanced metal hull structure.

Following this study, Hiro designed a new flying boat, closely resembling the Southampton.

[2] The new aircraft was a twin-engined biplane, with an all-metal hull and fabric covered metal wing and tail structures.

The first prototype was completed in 1930 and, following successful testing, was ordered into production - with thirteen aircraft being built by Hiro and a further four by Aichi.