If you knew anything about those languages, you would likely know how they developed and changed over time relative to each other (which is fairly common knowledge). You see, genius, human beings migrated all over the world over a very long time. Peoples who settled in the area that is today China spoke a language quite different than the majority language Mandarin spoken there today, and very different from the languages that other peoples who migrated and settled in the area developed for themselves. The written Chinese language is logographic in nature. If you look at a more ancient form of Mandarin you can see the symbols that at first directly represented objects from nature change and develop into more abstract shapes over time as the language changed (as all languages do over time). Abstract ideas and specialized symbols representing markers to indicate pronunciation came into the language and also changed over time. China was not handed a finished language and then placed by a giant hand made of clouds into the area of China today. While all this was happening people continued to migrate and some humans moved into the area that is today Korea. The form of language that they brought with them also changed and developed into a distinct one very heavily influenced by Chinese. In
1443, King Sejong of Joseon dynasty created a new written language that codified and in ways altered the spoken language. At this time, the use of 'Chinese' characters became more limited in Korea. Only quite recently, Korean has come to use Chinese characters only rarely and the pronunciation, grammar, and syntax of the two languages are very different. But the story doesn't end there. People had all along kept on migrating, as we always do, and peoples from the Korean Peninsula had long since found their way to what is today Japan. Guess what happened? That's right, the languages people brought with them changed and developed distinctly over time (as languages always have). The indigenous Ainu people already spoke a unique language that developed in their relatively long isolation there. Once again, the two languages influenced each other and developed further into a more and more distinct form. Again, the people who migrated to the Japanese islands at first used Chinese characters. This too changed over time so that today Japanese uses two interpretations and pronunciations of Chinese characters as well as two different syllabaries and yet another one to represent more recently introduced words from other languages. Gradual, systemic, and inevitable language change over time. All without taking a ticket like at the deli and waiting to be placed in a given place and handed a completed and unchanging language by a giant hand made of clouds.
All of this merely scratches the surface of just one very clear and easy to follow branch of human migration and language development.