An online petition calling for the Tokyo Olympics to be cancelled has been signed by over 230,000 people in just two days.
The Games were already postponed from 2020 due to the coronavirus.
Now, with just 11 weeks to go, Japan's medical system is currently struggling through a fourth wave and a sluggish vaccination program.
Kenji Utsunomiya organised The "Stop Tokyo Olympics" petition:
"At this moment, hospital workers are exhausted. On top of this they would find it difficult to help with the Games. I recieved a phone call from a hospital worker this morning who thanked me for (organizing the petition) and speaking out on their behalf."
Games organizers and the Japanese government have repeatedly said the event needs to go ahead, in part as a symbol of the world's triumph over the pandemic.
They say detailed COVID-19 protocols have been unveiled for participants.
Opinion polls have found a majority of the Japanese public is opposed to the Games.
The government has extended a state of emergency in the capital and three other areas until the end of May.
On Thursday, Pfizer and its German partner BioNTech agreed to donate their vaccine to inoculate participants.