The parks fear that thrill-seekers will produce droplets through screaming and shouting, which increases the risk of spreading COVID-19.
When the Fuji-Q Highland theme park reopened on at the start of June, it followed the advice of the amusement park association and asked visitors not to shout or scream.
Though keeping quiet did not prove to be a problem on the smaller rides, customers complained it was near impossible to keep the noise down on the two-kilometre-long Fujiyama rollercoaster, which reaches speeds of 130km/h and has a 70-metre drop.
In response to customer complaints, the park released a video of two stony-faced executives riding Fujiyama without making a sound to prove it could be done.
The bizarre clip shows the two men riding the roller coaster while maintaining their serious expressions throughout. Both are wearing masks and are dressed formally.
The video urged visitors to “please scream inside your heart."
Fuji-Q then asked customers to post videos of their silent rides on social media, with everyone who does being entered into a prize draw.
Japan has not been severely affected by the coronavirus pandemic and did not implement a strict lockdown like many other countries, but did ask non-essential businesses including theme parks to close.
Most have now reopened, with masks compulsory at all of them.
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