This tradition of welcoming the spring that dates back to the 12th century is still going strong. It is arguably also the best time to meet and mingle with Japanese people as they let their hair down.
For a small and delicate flower, the cherry blossom is very big in Japan. After a long grey winter, the blooming of these pale pink flowers that herald the arrival of spring is eagerly anticipated across the nation.
In the weeks before the blossom's bloom, companies' portable karaoke machines are dusted off and new recruits are instructed on the importance of reserving the best spot for the company's annual "hanami" revelries — a ritual that can trace its roots back to the samurai of the 12th century Kamakura period.
Back then, the elite imperial courtiers paused to appreciate the delicate pink cherry blossoms known as sakura before indulging in picnics and poetry sessions beneath the blooms.
A millennium later and the flowers that inspired a thousand haiku are no less revered in modern-day Japan. Hanami literally translates as "looking as flowers," and refers to flower appreciation picnics under the blooms. University friends, school groups, neighborhood associations and families all prepare picnics, drinks and the ubiquitous blue tarpaulin to lay out beneath the elegant pink flowers.
It's the best time to be in Japan. As well as the natural beauty of spring here, the average Japanese, typically retiring and shy to the point of muteness often out of fear that a verbal faux pas will offend and cause personal loss of face, is more relaxed.
During cherry blossom season, social conventions are forgotten and a passer-by is likely to receive a mildly inebriated invitation to join a group's revelries.
Few things are as quintessentially Japanese as cherry blossom — these flowers are up there with Mount Fuji and geisha as indisputable motifs of the nation. Indeed, the progress of the opening of the blooms is followed with near-religious zeal. Newspapers and television news programs carefully chart the northwards advance of the arrival of the blooms on maps, with commentators expounding on the significance of the early or late arrival of the blossoms.
The first to bloom will be the "somei yoshino" variety, which is so pale that it is almost white, followed by the "shidarezakura" and finally the deeper pink of the "yaezakura."
For the first two weeks of April — if the weather is kind and the trees can retain their flowers — several of the biggest public parks in and around Tokyo, plus the grounds of shrines and even graveyards, will be the scenes of large-scale over-indulgence that ushers out the winter and welcomes the new business and school years.
And then, when the last flower has gone, Japan goes back to business-as-usual. The public letting down of hair is as brief as the passage of the cherry blossoms themselves. Every city in Japan will have numerous locations where "hanami" parties take place, but here are some examples.
Tokyo - Ueno Park
This sprawling public park, slightly to the north-east of central Tokyo, used to be the grounds of the Kaneiji Temple but became the city's first western-style park in 1873. There are a number of museums in the grounds, but these are largely overlooked during cherry blossom season.
The park is bisected by a wide boulevard lined by cherry trees with low branches that meet overhead, giving the impression of walking down a pink tunnel. "Hanami" revelers line both sides of the road with their tarpaulins and the singing and drinking goes on long into the evening.
Do not be surprised to see a business man, referred to here as a salaryman, fast asleep in his suit covered with a light sprinkling of pink petals.
Yokohama - Negishi Shinrin Park
This park, in the Negishi district to the south of Yokohama, was originally the site of Japan's first western-style horse racing track. After the Second World War, it was turned into a large vehicle depot for the US military before being handed back to the city in the 1970s and transformed into a beautifully landscaped park.
There are reportedly more than 350 cherry trees throughout the park, the majority forming a vast bank that stretches along one of the gently sloping hills. Others can be found in groups close to the pond or near the derelict grandstand, which is the only surviving reminder of the park's previous incarnation. This cherry-blossom viewing venue is popular with local families who stake out their claims early in the morning on weekends when the flowers are in full bloom.
Kyoto - Philosopher's Walk
This flag-stoned path runs for around 2 kilometers (1.25 miles) and links Ginkakuji, better known as the Silver Pavilion, with the Nazenji district to the north of the ancient capital. The route follows a narrow canal lined by hundreds of cherry trees and smaller temples and shrines. The path is named after Nishida Kitaro, one of Japan's most famous philosophers who reportedly practiced meditation as he walked this route on his daily journey to Kyoto University.
Osaka - The Japan Mint
The grounds of the nation's mint may not seem the obvious place to admire cherry blossoms, but the facility occupies a prime spot alongside the Yodo River and opens its gates every spring to hundreds of merrymakers.
The grounds of the mint have around 350 trees and no fewer than 134 varieties, meaning that the party starts earlier thanks to the early-blooming species and goes on longer than elsewhere.