It depends on the property you want to rent. Some properties accept applications from people planning to come to Japan. In this case, you may be required to submit a copy of your Certificate of Eligibility or visa application. Please note that in principle, reservations for more than one month cannot be made, regardless of whether you come to Japan or before, especially if the room is vacant.
It varies depending on the property. Furnished apartments are available, while unfurnished rooms include furniture and appliance rental services.
In recent years, many properties are requiring the use of a guarantee company, regardless of the nationality of the tenant. For such properties, you do not need to provide your own guarantor or joint guarantor. However, if you use a guarantor company, you will usually need to have an emergency contact. Some guarantee companies may require a Japanese contact person.