The Kanto area includes the megacity of Tokyo, its many suburbs, and the flat plane that surrounds it. Kanto dialect is considered to be standard Japanese and it’s what you learn in Japanese textbooks.
Like the flat plain where it’s spoken, the intonation of Kanto dialect is fairly flat. There’s not much in the way of intonation or emphasis on certain syllables. Still, it has its quirks. Tokyo people are known for putting sa at the end of everything they say. They say jyan (sounds like “John”) to mean ja nai (in English this would be something like “you know?” or “right?”).
Kansai includes Osaka, Kyoto, Kobe and surrounding areas. To speakers of standard Japanese, Osaka sounds either charming and funny, or grating and obnoxious. There’s a sort of Tokyo-Osaka rivalry and both areas have great pride in their way of speaking.
Kansai people generally change the way they talk when they move to Tokyo, except for times when they want to be charming or show their Kansai pride. This is the dialect spoken by comedians (many of whom are from Osaka) and TV gangsters.
Like the people of Kansai, their dialect is livelier. It has much more intonation and is generally spoken faster. They have their own words like akan, which means the same as dame in Tokyo speech (“no good.”). They use –hen as the negative verb form (wakaranai becomes wakarahen). They also say maido for “thank you” and when asked how it’s going, they say bochi-bochi, which means “alright.”
Although Kyoto people technically speak Kansai dialect, Kyoto’s speech is slightly different. To most Japanese, Kyoto speech is considered beautiful and elegant, especially when spoken by women. They use more formal expressions and verb endings that are actually the remnants of an older form of Japanese.
Tohoku is the northern part of Japan’s main island Honshu. Tohoku is so hard for most Japanese to understand that they use subtitles when Tohoku speakers are on TV. It’s often said that Tohoku people speak without opening their mouths. Tohoku people reply by saying that it’s too darn cold up here to talk, and you’d do the same if you lived here.
Two of the most common features of Tohoku dialect are drawing out the vowels to make them longer and blending diphthongs. They also change consonant sounds (for example, /k/ becomes /g/) and sometimes insert an “n” before “g” to make it “ng.” These features lead Tokyo people to generally consider it a lazy, country hick way of speaking.
The western islands of Japan have many different dialects. One of the most prominent is that spoken by people in Kyushu. Among its idiosyncrocies is using batten for “but” (instead of demo) and daken for “so” (instead of dakara). Kyushu folks are also known for ending questions with to instead of no.
Okinawan is not a dialect of Japanese; it’s a completely different language. It’s spoken by the Okinawan natives. It has an entirely different phonetic system and whole different words. Anyone who has been there knows mensore, which means welcome. It’s something like aloha in Hawaii. There are many different languages spoken in the islands and they are all listed as endangered languages by UNESCO.
Absolutely every corner of the Japan has its own dialect if you go deep enough into it and find some real locals. Where I live in Chiba there’s a specialized vocabulary used only by fishermen on the prefecture’s east coast. Because these dialects of Japanese are so diverse and different from one another, it’s a fascinating subject for people who are learning Japanese.