Here are some relevant sources of information
The Japanese authorities have established consultation centres in local public health centres throughout Japan. For English language assistance, including on finding medical facilities or support in relation to COVID-19, please contact the advice line of your prefecture (PDF, 736.7 kB).
The Tokyo Metropolitan Government TMG provides information regarding cases of pneumonia associated with the novel coronavirus. Also, NHK World Japan provides information on their news website.
The Federal Office for Public Health FOPH has the expertise to advise on the virus and is therefore in a position to advise on health issues.
For more general information on the virus, you can also consult the website of the World Health Organization.
safetravel.ch (DE/FR) also publishes addresses of Institutes for travel medicine.
The travel advices of the FDFA (DE/FR/IT) focus on safety information related to the fields of politics and crime. They contain an assessment of possible risks and recommend certain safety measures.
If you are Swiss and travelling abroad, register now on the "Travel Admin App". This will enable the FDFA to provide you with better support on your return journey.
Swiss travellers abroad should register on the "Travel Admin App”
The Japanese Ministry of Justice publishes information related to immigration control and denial of landing, in English.
For further information about entry in Switzerland, please consult the website of the competent authority in Switzerland, the State Secretariat for Migration.