The inspiration people seek: If you ask people in Japan what comes to mind when they hear the words “iced coffee,” most will probably answer with, “Summertime,” or, “A kissaten.” No picture of the Japanese summer would be complete without things like the flag boldly decorated with the Japanese character for “Ice” fluttering in the breeze in front of a kissaten on a hot afternoon, the sign in the window of the local Chinese restaurant announcing that hiyashi chuuka—a chilled ramen noodle dish—is now on the menu and the evening crowds at a summer festival gaily dressed in bright summer kimonos. And of course, there’s that invitingly chilled glass of amber-brown iced coffee with beads of condensation on the outside that makes you feel cooler just by looking at it. Read more The refreshing clink of ice cubes in a glass of iced coffee is one of the nostalgic sounds associated with summer in Japan, alongside the gentle ring of wind chimes (fuurin) that seem to soften the glare of the summertime sun, the distant sound of fireworks (uchiage hanabi) bursting in the night sky and the soft crackle of sparklers (senkou hanabi) in the garden.
Glasses of iced coffee are essential props in Japanese movies and novels as well, and their appearance will usually conjure up scenes of the story’s main characters meeting and conversing. Especially in the era when movies were the biggest form of entertainment, a plot twist or drama-charged commotion staged in a kissaten were scenes that audiences came to expect and savor. An unforgettable one that would create the enduring image of the “charming lady” for some generations of Japanese audiences was the scene from Roman Holiday where Audrey Hepburn experienced the delights of a café for the first time, though the drink served in that scene was technically “cold coffee,” and not iced coffee.

In short: Iced coffee is the common name in Japan for a glass of coffee chilled with ice cubes. Although it is generally in the same category of “chilled coffee” customarily enjoyed in similar ways in Europe, such as French café mazagran or Italian caffe shakerato, the fact that it’s called “iced coffee” in Japan suggests that a very Japanese way of serving and drinking the beverage has developed here. (However, saying “iced coffee” with the Japanese pronunciation of aisu kouhee leaves many English speakers guessing as to what was just ordered.) Read more In Japan today, regional differences in dialects and culture are diminishing, but at one time, iced coffee was commonly called reikou in the Kansai region around Osaka, a word combining the Japanese word for cold or chilled (rei) and the first syllable of the word coffee, which is a quite typical way of making abbreviated words in the Japanese language. However, its use is also disappearing among the younger generation. (If this more Japanese naming had spread nationwide instead of the more English-sounding “iced coffee,” a lot of the confusion when Japanese travelers try to order the drink overseas might have been avoided.)
By the way, the “coffee gyunyu” (bottled coffee-flavored milk) that is the ubiquitous drink enjoyed after a hot soak at a Japanese bathhouse is also served cold, but it’s still a completely different type of drink from iced coffee.

Some background: It’s believed that coffee was first brought to Japan in the 18^th century. However, that was still when foreign contact and trade were strictly controlled and, as with other things foreign, this new drink called kouhee in Japanese was known only by a small number of people. Read more Even after Japan opened its borders in the Meiji Period (1868–1912), only the privileged upper class and university students acquired a taste for kouhee. At the time, when parody and caricature were popular with the common people, coffee drinking even became the stuff of jeers and jokes, much like the awkwardly Westernized parties put on at the Rokumeikan Villa in Tokyo for Western dignitaries. It wasn’t until Japan entered its next era of dramatic change after 1945 when kissatens began to spring up around the country’s cities that coffee finally became a popular drink.
That was also the time when “iced coffee” became a common item on the menu. As kissaten became a popular place to spend time and refrigerators finally came to many households, iced coffee became an integral part of the hot Japanese summers. Although today you may see it on tables at any time of year, around thirty years ago, iced coffee was a seasonal drink that appeared at the start of summer and faded away again with the coming of autumn.
Regardless of whether you accept the common theory that iced coffee is another case of “exported” Japanized culture, the popularity of iced coffee in recent years seems to be on the rise worldwide. You can now enjoy “iced coffee” in many countries at major coffee shop chains that are operating globally. If the theory is true, iced coffee is truly a prime example of Japan’s long tradition of adopting foreign things, adding a unique Japanese touch and returning the favor by exporting it in its newly evolved form.

Thanks to Sabouru (Coffee shop Sabor)