Tokyo (Agence France-Presse) - Japan's leading toilet giant opens a new museum this week dedicated to a century of lavatories, from its first water flushing model to the most cutting edge version with odour-neutralisers and variable water jets.

The museum operated by Toto - best known for its bidet-equipped Washlet series - opens its doors today in the south-western city of Kitakyushu where the company is based. Admission is free.

High-tech toilets, common in Japan, regularly win praise from foreign tourists and celebrities as the epitome of Japanese know-how - a contraption that offers both comforting warmth and a frighteningly accurate bidet jet. International stars who have sung the praises of Japan's bidet seats include Madonna and Will Smith.

The seats are also among the most popular items targeted by Chinese tourists, ranking alongside high-spec rice cookers and cosmetics.

The museum's exhibits includes a replica of Toto's first water flushing toilet seat, which came onto the market in 1914. Also on show are remakes of washrooms that it supplied to major buildings across Japan, including the State Guest House in downtown Tokyo where foreign dignitaries stay and those installed at a luxury hotel for the 1964 Summer Olympic Games in Tokyo.

Nearly every household in Japan and many public restrooms are equipped with a seat that is plugged into the mains electricity. At their most basic, they simply get warm and spray warm water for rinsing while those at the upper end boast motion sensors, high-power odour-neutralisers and variable water jets, all tailored to conserve energy and water.