It's akin to straying into a cartoon. From the sun-drenched yellow walls, to the maze of spiral staircases and mini-sized archways beneath painted-dome ceilings – not to mention the over-sized furry cat bus and a towering robot loitering in the roof garden – the scene would not look out of place in a raft of animations. However, it is in fact one of Japan's very real anime gems: the Ghibli museum.
Japan, the birthplace of anime, has been a master of the cartoon artform since producing what is believed to be Asia's first animation in 1917. With a style initially inspired by Japanese painting and calligraphy, the nation's prolific cartoon productions began booming in popularity among overseas audiences from the 1980s.
Today, it's a huge part of Japanese culture. The anime market in Japan was valued at 216.4 billion yen (£1.7bn) in 2009. Anime lovers – known as otaku in Japanese – think nothing of queuing around the block (often dressed as their favourite characters) to watch the latest film release.
Located in the leafy green Mitaka neighbourhood of Tokyo, the Ghibli museum is for anyone who has ever appreciated the beauty and imagination of Japanese animation. Its founder is Hayao Miyazaki, a Japanese artist and director who won legions of awards for the films produced by his company, Studio Ghibli. Among a long list of critically acclaimed works are Spirited Away, the tale of a girl whisked away to a spirit world in a bathhouse, Porco Rosso, with its debonair anti-fascist pig pilot protagonist, and Princess Mononoke, which won numerous awards.
Studio Ghibli's latest film, released this weekend in the UK, is Arrietty. It tells the tale of a tiny-sized family of "Borrowers", and is based on the characters in the books by Mary Norton. Audiences should brace themselves for the lush water-colour visuals that have become the signature style of Studio Ghibli productions, where computer graphics are shunned in favour of hand-painted cartoons.
It is such a world that Miyazaki has attempted to recreate at the Ghibli Museum. Despite its name, it bears little resemblance to conventional museums. There's not a minimalist white wall, "don't touch!" sign or black-suited security person in sight.
This is deliberate. Outlining his vision for what he did not want this museum to be, Miyazaki said: "A pretentious museum. An arrogant museum. A museum that treats its contents as if they were more important than people." Instead, he said he wanted it to be "a museum that is interesting and which relaxes the soul... a building where the breeze and sunlight can freely flow through".
The sweeping staircase at the entrance leads into the main lobby of the house. The exhibition space on the ground floor is devoted to the mechanics of animation. A string of models of Ghibli characters speed up and slow down in various displays: there is the robot from the film Laputa surrounded by blue flying birds, and a colourful 3D zoetrope depicting a spinning cast from My Neighbour Totoro.
As I wander up to the first floor, another cartoon-like scene shifts into focus: it's a cosy office crammed with an array of fantastical objects, from plane models and flying dolls to antique globes and teetering piles of references books.
"Ah, there's Arrietty!" exclaims one Japanese girl to her friends. She is pointing at an image of a pretty pint-sized young girl with a swinging pony tail, red dress and defiant expression among hundreds of hand-drawn sketches adorning the walls.
The use of paper is part of the Japanese psyche. "Unlike the Europeans who build massive structures of marble or stone, the Japanese tend to assemble low-level buildings out of wood and paper," says Junichi Nishioka, Ghibli's spokesman. "The reason for such a cultural contrast is the frequency of earthquakes in Japan. Therefore, rather than decorating homes with sculptures, the Japanese prefer paintings drawn on paper."
Instead of loitering behind conventional museum barriers, visitors can sit at the desks, leaf through photo albums, or pick up and read a book. A coffee pot sits on the stove, a bicycle (whose bell, I can attest, rings nice and loudly) is parked nearby.
Some small children are drawn to another space on the first floor: an area where scenes from Studio Ghibli's films have been recreated. In one room sits the giant furry cat bus from My Neighbour Totoru in which visitors can sit and look at the passing scenery.
Another highlight is wandering around the maze of gardens and terraces and finding a spiral staircase which leads to the roof – where a startlingly large robot from Laputa stands, legs akimbo, among the overgrown flower bushes.
Perhaps the best part comes at the end: a 10-minute screening of an original Miyazaki anime in the in-house Saturn Cinema, complete with children-sized red seating and a ceiling painted with a smiley moon and sun.
Later, sitting under umbrellas in the Straw Hat Café, I tuck into a cooling Japanese pear ice cream while surveying the other visitors. There are countless babies, toddlers, schoolchildren and teenagers – but perhaps the happiest smiles of all can be found on the faces of the anime-loving grown ups.
'Arrietty' is in cinemas now
* Tuck into a pizza (Y590/£4.60) branded with the face of Gundam the robot – a character from the cult anime series of the same name – at this café in Tokyo's Akihabara district, a hub for anime lovers (00 81 3 3251 0078; g-cafe.jp).
Tokyo Anime Center
* Also located in Akihabara, the Anime Center is a magnet for international devotees of Japanese cartoons, and is home to events, live shows and fairs. Admission free. (00 81 3 5298 1188; animecenter.jp).
* Step on board Himiko, a water bus with flashing panels and 3D bubble windows, designed by anime artist Leiji Matsumoto, and watch the sun set over the futuristic skyline in Tokyo Bay. It costs Y760 (£6) for a 40-minute cruise (suijobus.co.jp/english).
Travel essentials: Tokyo
* British Airways (0844 493 0787; ba.com) flies from Heathrow to Tokyo Narita and Tokyo Haneda. Virgin Atlantic (0844 874 7747; virgin-atlantic.com), All Nippon Airways (0870 837 8866; anaskyweb.com) and Japan Airlines (08457 747 700; jal.com) fly from Heathrow to Tokyo Narita.
* Regional departures are available with airlines such as Emirates (0844 800 2777; emirates.com) and KLM (08705 074074; klm.com) via their hub cities.
* Ghibli Museum, 1-1-83 Shimorenjaku, Mitaka-shi, Tokyo (ghibli-museum.jp/en). You must buy a ticket in advance; these are available via designated travel agents in the UK (020 8237 1605; japanspecialist.co.uk and 020-7976 1191; mybus.co.uk/apply) or from Lawson convenience stores in Japan. Entry Y1,000 (£7.30) for adults, Y100-Y700 (80p-£5.50) for children aged four to 18 (under fours free).
* Japan National Tourist Organisation: 020-7398 5670; seejapan.co.uk