Horrid slimy things, mushrooms. I've never liked them. So I'm not tempted by a box of three pale brown fungi on sale at a stall in Kyoto's food market.

That's just as well, because they cost 37,000 yen, or about £250. Fans of Japan often say its reputation for emptying a tourist's wallet faster than you can say "konnichiwa" is exaggerated. What's certainly true is that if you spend a lot in this land of high design, delicate aesthetics and unfailingly polite service, you're spoilt silly.

About Y25,000 (£169) buys a night at a top ryokan, a traditional inn where pampered guests can gaze out at bonsai gardens from the comfort of a private bathtub. There's no limit to luxury here. There are more three-star Michelin restaurants in Tokyo than any other city. Bullet trains are stupidly fast, punctual, clean – sexy, even. Your fellow travellers disport themselves without jostling or eating smelly food, meaning you can actually enjoy the journey. But a regular return fare from Tokyo to Kyoto on the fastest Shinkansen service, the 180mph Nozomi Super Express, will also tear Y27,040 (£182) from your purse.

So, my challenge was to take a two-week trip around the big-ticket sights of Honshu, seeing Tokyo and Kyoto, plus some of the prettier places in the "Japanese Alps" – keeping to about Y10,000 (about £67) each a day. It wasn't a shoestring; my days of sleeping in dorms are over. I've been to Japan twice before, on business, but this time I wanted to see more; my boyfriend had never been but had learnt some Japanese and was keen to try it out. Our plan was to sleep in cheaper, chain business hotels and budget ryokan. We'd use buses and local trains but we still wanted to eat decently, buy small souvenirs and experience some only-in-Japan moments.

The solution was a new self-guided tour offered by Inside Japan, which would pre-book accommodation and travel. The "Price Cruncher" tour also meant we knew how much the trip would cost: the only variables would be food and spending money.

We start in Tokyo, regularly at the top of any "most expensive city" charts. But there are plenty of free amusements: a 6am visit to the Tsukiji fish market; walking in the Imperial Palace Gardens; watching sumo wrestlers practise; and the view from the 45th floor of the Tokyo Metropolitan Building, Shinjuku.

Living frugally can't keep me from touring the city's ritzy department stores and gleaming malls. But, like lots of Tokyoites right now, we just look. It's easy not to buy clothes when your giant limbs would split Japanese XL sizes at the seams. The gourmet shops in department-store basements are harder to resist.

I soon give in to the call of consumerism, but keep purchases small – not the latest micro-camera, but what I'll call "cuteware". The country's unofficial religion is still the worship of all things kawai (cute), and for a few pounds you can load up on Miffy calendars, stickers, fun-fur ashtrays, glittery hair clips, and strapus (the mini toys that dangle from every mobile phone). Recession has meant good times for the 100-yen shops, which trade in cheap knick-knacks, household essentials and sometimes food.

Tokyo's subway system requires concentration to navigate (with the help of an English-language map), but it's affordable. We buy pre-paid Pasmo cards and load them with credits,

although unlike London's Oyster system there's no saving on the standard ticket. Expect to spend about Y1,200 (£8) a day for about six journeys.

After four jet-lagged, beer-soaked nights in Tokyo, we're wrung out, so we head to the mountain resort of Hakone on the Odakyu Highway Bus (Y1,850, or £12.50), which is, they say, a great way to see Mount Fuji. (It's hidden in mist when I travel, so I'll take their word for it.)

The next morning, to get to Kyoto, we take the bullet train – the most expensive leg of the trip at Y6,000 (£40) for a reserved seat – and savour the journey. It'll be coaches and local transport from now on.

Hidden away at edges of the city, the antique pavilions, Zen gardens and pagoda architecture are captivating – but entry tickets average at Y500. We search out less popular sites, which are not only more peaceful but cheap, or even free. The best is a sprawling compound of Zen temples called Daitokuji. Here, the minuscule ryogen is a perfect jewel of five dry gardens, each about the size of a tiny city roof terrace, and each symbolising with moss or rock or gravel a lovely, if obtuse, piece of Buddhist philosophy. Entry costs a mere Y300 (£2), and it is deserted.

Kyoto's gardens require lots of walking, and, for me, that takes caffeine. Blowing Y400 (£2.70) at Starbucks is out, so I get familiar with the vending machines on every corner.

I had thought a formal Japanese tea ceremony was out of reach until I hear about a place in the small town of Uji, just south of Kyoto. Here, in a tea house next to the tourist office (where you buy the ticket), is supposedly the cheapest tea ceremony in Japan. The hot, fluffy, bright green liquid you drink at the end of cha-no-yu, or "way of the tea", isn't the point, of course. We're offered a place to kneel, while two ladies in brocade kimonos and elaborate hair split duties: one heats the water on a brazier and whisks the tea; the other kneels behind her, keeping one eye on her technique, while also making stilted conversation. It's like visiting a great aunt, but the tea ceremony is a showcase of traditional Japanese etiquette. At 20 minutes and just Y500 (less than £3.50), this was short order compared with the average Kyoto experience (45 minutes or longer, for Y2,000, or £13.40).

Back in modern Japan, eating fast, furious and cheaply isn't a problem. At lunch, restaurants offer a cheaper set menu. We slurp in noodle restaurants, where a big bowl of thick udon noodles in hearty soup stock are layered with slices of pork, just Y850, less than £6, in an Ebisu branch of the hip noodle chain Ippudo.

Conveyor-belt sushi restaurants with colour-coded plates helps avoid shocking bills, though you'll watch the priciest dishes glide by. Bento boxes are cheap and easy to select; okonomiyaki, an omelette filled with sliced cabbage, or noodles, with egg, slices of beef or fish, is yours for Y750 (about a fiver). Our favourite frugal dinner is yakitori, chicken skewers cooked to order as you sit facing the grill.

A step up from McDonald's, places such as Jonathan's, Royal Host and Yoshinoya are the equivalent to Pizza Hut, with a Japanese level of service and quality. My favourite is the "Italian" chain Saizeria: portions are modest but the flavours are decent and the picture menus are easy to use. A bowl of penne all'arrabiata and a glass of drinkable French red wine is Y600 (£4).

Two hours and 20 minutes from Kyoto on the limited express train (Y6,800 or £46) is the coastal town of Kanazawa, with famous ornamental gardens and a sleek new contemporary art museum. We spend the afternoon in the "Ninja Temple", a castle of tricks with hidden staircases and sliding doors designed to confuse invading enemies. The price is rather sly, too, at Y800 each, and by now the budget's getting tight so we start hanging out in games arcades; bigger places have their own "maid cafés". Sadly, nowhere do I find a budget karaoke venue to parrot my favourite Eighties' hits – the ubiquitous chain Big Echo charges Y2,000 (about £13.50) per hour. Too expensive.

The end of our frugal tour rounds the mountains west of Tokyo, through Takayama, home to Hida beef, which locals obviously hope can challenge Wagyu and Kobe varieties. Next day, in Matsumoto, two hours away by carefully driven coach (with filmic views of rusty autumn leaves), we spend the afternoon in the most beautiful castle I've ever seen. Five tiers of beautiful blackish wooden pagoda, reflected in koi carp-filled waters. On a war footing after a sturdy curry noodle lunch (Y525 a bowl), we march up the wooden steps inside the 16th-century keep with legions of school kids. Entry fee? A mere Y600 each (£4 – the Tower of London costs £16.50).

By the end of the fortnight, we meet our daily budget but the ruinous exchange rate didn't help. Our "self-guided" tour package gave us all the train and bus tickets beforehand and helped us sidestep expensive mistakes. A couple of practical tips: debit and credit cards are not as widely accepted here as in the UK, and post offices are the only place where foreign-issued cards work – so you need to carry cash. It's safe to do so, but the Y10,000 (£67) limit per transaction at a post office ATM means bank charges can tot up.

The Japanese have got used to living in recession, and there are bargains here – you just have to find them. I didn't feel like the Queen of Sheba, but everything I ate, drank and looked at offered amazing value – except for those mushrooms. They were definitely overpriced.

Compact Facts

How to get there

Susie Rushton was a guest of Inside Japan Tours (0117-314 4620; inside japantours.com). Its 13-night Price Cruncher trip costs £1,217 per person, based on two sharing, with five nights in Tokyo, one in Hakone, three in Kyoto, one in Kanazawa, two in Takayama, and one in Matsumoto, plus all breakfasts, one dinner and all transfers. A seven-night version costs from £600. Japan Airlines (0845 774 7700; uk.jal.com) offers daily flights from London to Tokyo from £589.

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