What is Japan really like? I have been trying to answer that question for 20 years. My answer always depends on when and where I am asked.

Coming up with an answer at all requires imagination. Japan is primarily an act of imagination. The Japan imagined after viewing gardens of Zen temples couldn’t be more different from the Japan imagined after reading this entertaining book by Tokyo-resident and Guardian journalist, Justin McCurry

The book is about keirin, a type of indoor cycle-racing in Japan developed in 1948. The government introduced the sport as a way of controlling gambling and raising revenue for local governments.

Keirin does not have the prestige of sumo or the popularity of baseball in Japan. Yet it is a distinct Japanese sport recognised around the world. A modified version is now a popular Olympic event.

The differences between Olympic and Japanese keirin are reflected in the orthography. The original keirin uses the kanji combination 競輪 (lit, competing wheels). The modified Olympic version of keirin is expressed in katakana, ケイリン.

Living in Japan for 9 years, I was only ever vaguely aware of the existence of keirin. There is a good reason for this. Keirin exists on the very fringes of culture and society: a a long-standing reputation for gambling and violence mean velodromes are purposely built away from residential areas, races receive little media coverage, and the competitors aren’t celebrities.

So, what’s the point in it? Well, it makes money for local governments, creates employment and provides entertainment, even if it is for spectators just to shout abuse at the cyclist you hold responsible for losing your investment.

The angry old-man element of keirin crowds is brilliantly brought alive in the book. The keirin punters cursing the competitors are a world away from the fan-friendly environment of football matches in Japan where the opposition are applauded and everybody takes their rubbish home.

The author’s enthusiasm for keirin shines throughout. The book is a product of a huge amount of research and interview. As well as outlining the history and dynamics of a keirin race, the book also profiles international keirin, the rise of women’s keirin and the new online late-night-races that could save keirin from collapse.

Keen on a flutter himself, Justin McCurry clearly loves the thrill of the race. I particularly enjoyed the description of the kanji-covered betting slips that tell you everything from the rider’s star sign to their thigh size.

The riders themselves are the heroes of the book. They come across emerge as a cross between a salaryman in a saddle and a warrior on wheels. The riders fierce dedication and sacrifice keeps the sport alive.

This little-known sport clearly plays a big-part in the lives of many Japanese. Like or loathe it, keirin culture is a part of what Japan is really like.