The Japanese call it Sakura Zensen - the cherry blossom front - and its arrival is treated as a gift from the gods.
Indeed, some cherry trees have been designated gods and honoured at shrines.
It is a time when the serious business of work gives way to serious sake parties
among the drifts of flowers, when salarymen loosen ties and in their drunken reverie compose haiku (poems) to this time of fleeting beauty.
At one such party Canadian Will Ferguson, an English teacher, proclaims to his colleagues that in order to discover the true heart of Japan he will follow the cherry blossom front by hitchhiking the length of the country from Cape Sata in the south to Cape Soya in the north, a distance of 3000 km.
His bluff is called when the school principal expresses his admiration for Ferguson's resolve.
Committed though Ferguson is to his journey, he is unnerved by his colleagues who are puzzled by the notion of hitchhiking Japan.
They offer to lend him money, to buy him a train pass, warning him that no one will stop to pick up hitchhikers, especially a Westerner.
But he's not worried because Ferguson is a man shamelessly in touch with his travel weasel side. A freeloader with attitude.
For the "big clumsy barbarian" the rule of thumb is be ready to drop hints, look pitiful and to choose a likely mark as your motorist at every opportunity to avoid walking.
What unfolds is a travelogue that's a joy to read.
Ferguson shows the contradictions that are Japan. The fervent nationalism alongside the many random acts of kindness. The wearing side of being a foreigner, a freak.
"I remember a trip to a Japanese zoo, and how the children turned their backs on the caged wildebeest, and watched me instead. 'More interesting than a wildebeest' became my personal motto after that."
A funny, irreverent and insightful book.
On a more practical note, first-timers' planning a working holiday in Japan would do well to look out for the second edition of Louise Southerden's Japan: A working holiday guide (Global Exchange, $29.95).
It will help you prepare for the culture shock.
Hokkaido Highway Blues
By Will Ferguson
Canongate Press
RRP: $34.95