How about a trip to Japan Central Honshu

By far the largest city in the world in almost every conceivable way, but especially in sheer breadth and size, Tokyo is somewhere you cannot miss out if heading to the land of the rising sun. It is on a scale the likes of which nothing in Europe compares, and despite the sheer volume of its 35m+ inhabitants, is fastidiously clean and exceptionally safe! For a city of such enormity, there are few true “sights” to see that will be known throughout the world. The Shibuya district and its crossing, the Tsukiji Fish market, the Imperial Palace, stunning cherry blossoms and the Tokyo Sky tree. Don’t let this relatively short list allow you to think there isn’t a wealth of things to do here, there really is, they’re just less “shouty” about it than many other large cities.
Tokyo by day is busy, crowded, fun, friendly and enjoyable, but it’s at night when the city really comes alive, both in terms of entertainment, shopping, eating and visually. It is a visual and audible spectacle to behold and you really, just must witness it for yourself.
This is just about the only part of Japan, to any size at least, which is largely flat and mountain free… with perhaps one rather well known exception. Mount Fuji. One of the most iconic and photographed volcanos on earth, long dormant and climbed by thousands of people every day… on a clear morning (yes you need to start the climb very early!), the views are utterly spectacular as the sun rises over Tokyo below.
Centred around Japan’s second largest city, Osaka, south-central Honshu is a thriving, bustling, busy area with a wealth of attractions, including Osaka Castle, a truly gorgeous reconstruction of the original, one of the worlds largest aquariums, a whole host of ornate temples and shrines, a range of theatres and Universal Studios Japan! In addition, the shopping, wining and dining and accommodation are nothing short of superb, with more retail therapy than you could ever hope to exhaust, some truly exceptional restaurants as well as your regular fare and some of the finest hotels in the world. It really is a gem of a city!
The far south of the region is heavily forested and a true back-to-nature, type of place, feeling even more rugged than it might otherwise due to the proximity of 17m inhabitants only a few miles away and yet you could genuinely be in another country!