Whether the sun is shining or it's pouring with rain, there's always something to do in Osaka. the city is Japan's second largest metropolitan area after Tokyo and is well known for its striking architecture, rowdy nightlife, awesome street food, and, of course, Osaka Castle. If the weather is bad then don't worry because in the middle of the city's main shopping district is Shinsaibashi-suji, a large covered shopping street where you can easily spend a few hours while you're waiting for the rain to stop.