WATCH: What Makes Japan No. 1 In Toilet Technology

Japanese toilets have come a long way from the early 20th century, when many people in Japan still used "squatters," which were built into the floor.

Western toilets became popular after World War II. And today, signature Japanese toilets offer the world's most futuristic and automated technology when nature calls.

The units are not just toilets, but also bidets, offering a dizzying menu of options for washing and also for privacy — not to mention heated seats, automatic odor-neutralizers and lids that rise when you approach.

A Japanese government survey last year found more than 80 percent of Japanese homes have toilet-bidet combos.

Check out the Washlet — the name given to a popular toilet-bidet combo made by Japanese company Toto — and its more advanced cousins in this showroom tour. Toto is the world's largest toilet maker, with more than $5 billion in annual sales. Its Washlet line ranges in price from $400 to $1,800. Higher-end Toto Neorests, which count Leonardo DiCaprio and Madonna among its fans, can cost as much as $5,000.