Background: Non-consensual sex including rape and sexual assault has been a global concern and may have been influenced by the COVID-19 pandemic, however the information on this topic is limited. Therefore, our objective was to survey the incidence rate of non-consensual sex among Japanese women aged 15-79 years between April to September 2020, following the COVID-19 pandemic in Japan.   Materials and Methods: We utilized the data obtained from a nationwide, cross-sectional internet survey conducted in Japan between August and September 2020. Sampling weights were applied to calculate national estimates, and multivariable logistic regression was performed to identify factors associated with non-consensual sex. Data was extracted from a cross-sectional, web-based, self-administered survey of approximately 2.2 million individuals from the general public, including in men and women.   Results: Excluding men and responses with inconsistencies, the final analysis included 12,809 women participants, with 138 (1.1%) reporting experiencing non-consensual sex within a five-month period. Being aged 15–29 years and having a worsened mental or economic status were associated with experiencing non-consensual sex.   Conclusions: Early intervention to prevent individuals from becoming victims of sexual harm should be extended to economically vulnerable and young women, especially during times of societal upheaval such as the COVID-19 pandemic. Additionally, Japan should prioritize the implementation of comprehensive education on the concept of sexual consent.

TT reports personal fees from Medical Network Systems, MNES Inc., and Bionics co. ltd., outside the submitted work. AO reports personal fees from Medical Network Systems, MNES Inc., outside the submitted work. All remaining authors have nothing to disclose.

Yes

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Not Applicable

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

This study adhered to ethical standards in accordance with the 1975 Declaration of Helsinki, as revised in 2013. Prior to participating in the online survey, all participants provided informed consent through a web-based consent form. The Research Ethics Committee of the Osaka International Cancer Institute reviewed and approved the study (No. 20084).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Not Applicable

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Not Applicable

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Not Applicable

All relevant data are within the manuscript and its Supporting Information files.