Can that be done? Where?

I will be in Tokyo on business in October and will need a cell phone that accepts e-mail.

Many cellphones can accept email, however depending on the service it might not be able to accept email sent via the web, but only from another telephone.

However almost all modern phones allow one to browse the internet, so if you had a separate internet email address you can check your internet email using the phone without problems.

As you are not resident in Japan you will not be able to get a phone from city cell phone shops- you will need to get a rental one at the airport. There is an office in Narita (and I'm sure in Kansai if that's where you are arriving) where you can rent phones- look for it before you leave the airport.

Then tell them what kind of featured you need and they should be able to set it up for you. I can receive emails from computers on my cell phone, so that shouldn't be a problem.

There are many shops in Narita Airport that let you rent phones from all the major companies and minor companies, including stores in Tokyo, some major hotels also offer phone rental, not only in Tokyo but across Japan in major cities and airports.