An "intelligent" toilet that opens when you approach it and self-cleans with every flush is on display at the Consumer Electronics Show in Las Vegas.
It also cleans the user with an aerated wand, which delivers warm water and warm air "from a seated position", a spokeswoman said.
Despite a $9,800 (£6,704) price tag, more than 40 million earlier versions of the Neorest toilets have been sold.
Bathroom firm Toto said the new prototype was still in development.
Its self-cleaning process uses a combination of a disinfectant and a glaze - made out of zirconium and titanium dioxide - which coats the bowl.