Japan is one of a few countries that started developing the skyscrapers sooner than rest of the world, this is a bit different with other skyscraper cities, like Shenzhen or Dubai. Shinjuku Mitsui Building is the first skyscraper beyond 200 m built in Japan and was built in 1974, 19 skyscrapers above 200m in whole Japan area were built before 21 century.
Most of Japan's skyscrapers are concentrated in two cities, Tokyo and Osaka, while a few of them are located in Nagoya, Kawasaki, Hamamatsu, Fukuoka, Yokohama.
Tokyo is one of the cities with most skyscrapers, its skyline is one of the tallest in the world by average height. Although the city is lacking of supertall buildings, its skyscrapers are widespread and dense, these skyscrapers are not centered in a single district but can be found in many different regions, and also very dense in some regions like Shinjuku, making it looks more futuristic hence it is still preferred over other cities like New York City by some urbanity enthusiasts. Not only so, a kind of non-skyscraper buildings generally with white facades are densely spread in the whole city and filled into the gaps of districts of skyscrapers, these buildings looks just very modern though they are not tall.
Currently Japan has 3 supertalls built, one building in Osaka and two sightseeing towers in Tokyo.
Tokyo is the largest city in the world by total population, it's abnormal for Tokyo still not having a single supertall building, earthquake is not the main obstruction for the development of supertall buildings, as skyscrapers are considered and proved to be more secure, the problem is just the same with many other cities, that's the issue of flight paths over the central city region, including Shinjuku and Minato, Skytree is out from this region, the newly proposed supertall is also located relatively close to Skytree Tower.
Osaka is the second largest city of Japan, by the number of skyscrapers it's far behind of Tokyo but it has the country's first supertall building.
1. Tokyo Skytree Tower (東京スカイツリー)
Total Height: 634 meters
Roof Height (Antenna-removed height): 495 meters
Observation Deck: 450 meters & 350 meters
Built year: 2012
Function: Broadcast, Restaurant, Observation
Architect: Nikken Sekkei
Skytree Tower is the tallest structure in Tokyo and also the tallest broadcast tower in the world in today. It has become the new icon of Tokyo as it has appeared in countless Japanese films, some of which was filmed before its construction.
2. Tokyo Tower (東京タワー)
Total Height: 333 meters
Roof Height (Antenna-removed height): 254 meters
Observation Deck: 250 meters & 150 meters
Built year: 1958
Function: Communication, Observation
Architect: Tachu Naito & Nikken Sekkei
The appearance of Tokyo Tower was inspired by Eiffel Tower in Paris so they look similar to each other, this together with the red color make it an iconic structure of Tokyo, it had been the tallest structure of the city for half a century until in 2011 when it surpassed by Sky Tree.
3. Abeno Harukas (阿部野橋ターミナルビルタワー館)
Standard Height: 300 meters
Observation deck: 288 meters
Built year: 2014
Function: Office, Hotel, Observation, Restaurant, Museum, Garden
Architect: Cesar Pelli; Takenaka Corporation
Developer: Kintetsu Corporation
The first and the only one supertall building measured by both architectural height and roof height built in Japan.
4. Yokohama Landmark Tower (横浜ランドマークタワー)
Standard Height: 296 meters
Height above sea level: 300 meters
Observation deck: 273 meters
Built year: 1993
Function: Office, Hotel, Observation, Restaurant
Architect: Hugh Stubbins and Associates
Developer: Mitsubishi Estate
Technically it's not a supertall with an architectural height of 296 meters, but it's 300 meters above sea level, for a seaside building it makes sense to consider this measurement and having this tower in this list while currently Japan has only a few supertalls.
Tokiwabashi District Redevelopment Project Tower B (常盤橋街区再開発プロジェクトタワー B)
Standard Height: 390 meters
Stated built year: 2027
Developer: Mitsubishi Estate
Proposed in 2015, this building is the first serious and practical proposal for habitable supertall in Tokyo. If built, it will also become the chunkiest supertall building in the world by proportion.
Unfortunately the planned completion date is set to be in 2027, that's more than a decade from now, there's still a long way to go, maybe it will go through many changes in design or a height cut. With such a long period before the construction, it is highly possible that this project will gradually become a stale proposal, or even be replaced by other projects.