Tenga Onacups are a Japanese made brand of artificial vagina (called onacup in Japanese) with multiple models that feature different sensations for the user. It was first released in 2006 in Japan by its founder, Mr. Matsumoto, whose focus was to create a male sex toy with good design that didn't look cheap. By 2007, Tenga had sold over two million onacups and became the most popular male sex toy in Japan. Tenga also created a limited edition "Warming Stick" that can be activated and inserted into the onacups to warm the silicone to body temperature.