Nezura 1964

After visiting the Tokyo Zoo failed to inspire a creature concept, CEO Yuichi Nagano suggested using a mundane animal after watching a bird film. Tsukaji and Yuichi settled on rats because they were readily available and could be filmed in large numbers, making them practical for depicting a horde of monsters.

The production faced multiple crises: citizens near the studio protested over disease concerns from the rats, the Bureau of Social Welfare and Public Health sent a letter recommending termination, and on-set chaos with fleas and disease forced crew members to wear masks. These public health and safety issues made the project untenable.

Earlier protests had been brewing as local residents grew concerned about disease transmission from the rat colony.

Giant Horde Beast Nezura was a failed Daiei production that served as an early precursor to Gamera. After the project was cancelled, assistant director Kazuaki Yukawa visited CEO Yuichi Nagano on January 3 and saw a spinning firework that inspired a new monster concept, which was rushed into development and eventually became Gamera.

Citizens living near Daiei Studios protested on October 25, 1963, fearing the large rat colony gathered for filming would spread disease throughout the neighborhood. Their concerns proved valid when fleas and illness began affecting the production crew.

The decision to collect rats from the public and fill a warehouse with them had raised early alarms.

On November 3, 1963, the Bureau of Social Welfare and Public Health sent a stern letter to Daiei recommending the film's termination. This official government intervention, combined with the local protests, effectively ended any chance of completing the production.

The initial test footage filmed with domesticated rats proved troublesome because the animals were hard to control on set. Special effects director Yonejiro Tsukaji traveled to downtown Tokyo to capture wild rats, which filmed more successfully and convincingly for the monster sequences.

The Mammoth Nezura was a large puppet built by Daiei staff for on-screen action sequences. It was featured in battle scenes alongside the smaller rat creatures, with JSDF forces attempting to contain the monster threat during the fictional rampage through Tokyo.

On January 3, after the project's failure, Yukawa visited Nagano's home where he observed a spinning firework. This visual inspired a new monster idea that they rushed back to Daiei to develop, which ultimately became the basis for Gamera.

Screenwriter Hasebe's script included a joint US-Soviet lunar expedition, thematically aligning the film's premise with the space race era. The story involved experiments at the Mikami Space Laboratory that accidentally spawned the ravenous Nezura monsters.

After witnessing the project's failure and destruction, Yukawa reflected that Giant Horde Beast Nezura, while a failure, was valuable for teaching him about filmmaking. The experience contributed to his later success with the Gamera series.