The Queen Elizabeth II (Lake Sagami, west of Tokyo). What could be more natural? A 50-bedroom love nest shaped like a rusty ocean liner named after Britain's monarch. From a distance, it looks like the architectural folly of some mad Lothario, poised to plough into the waters of Lake Sagami. Up closer, it doesn't look any saner - and that's before you sample the treats inside, which include nautical sex-themed rooms and a gorilla for a captain. Adonis (Osaka, above). Hello Kitty and S&M - the only surprise is why nobody thought of it before. Japan's favourite cartoon character is given a work-over that would give children nightmares. If the sight of the bound and gagged stuffed cat suffocating in a plastic bag doesn't get your pulse racing, there's plenty more where that came from in this S&M-themed landmark set, bizarrely, in one of Osaka's temple districts. Chain yourself to ceilings, walls, crosses or, if you're a boring conventionalist, a bed. Gang Snowman (Osaka). You've hit it off with the boy/girl of your dreams and the night's activities inevitably lead to a rose-strewn road called Pleasures of the Flesh. The journey ends in the top floor of Snowman, where you take a bath inside a real Cadillac, have a water-pistol fight, tie each other to the S&M chair provided just in case the action flags, then watch a post-coital movie on a giant Snowman-shaped television. Sleep optional. Plaza 1 & Plaza Art (Tokyo, above). The love-hotel district of Shibuya fairly groans with treats for disciples of Eros, but if role-playing pushes your buttons. these establishments are for you. Dress up as a school-girl, stewardess, nurse or cop in costumes provided by the management, then take it all off again to bathe in the cave-shaped, hot-springs room or have a party (up to eight people) in room 902. The more women-friendly Plaza Art features tasteful ceramic breasts on the corridor walls and a giant butterfly in one of the rooms. You have to get closer before you notice that the butterfly has chains and cuffs attached. The Rock (Takasaki, Gunma prefecture, 100km north of Tokyo, above). Ah, love-making ... the sound of harps, the smell of red roses, the taste of bubbly - and the sight of a mock-up of Alcatraz prison. One of the most popular new love hotels in Japan, the Rock is inspired by the eponymous Hollywood blockbuster and features prison walls, rusting cages, robot wardens and security doors that open only after they scan your hand. Despite appearances, the rooms are disappointingly comfortable with nary a whip, chain or gagged cartoon character in sight.