"Mitai" and "you" means the same. They are 90% interchangeable. *** What is "you" It is 様（you), a Chinese-originated word, which means "appearance" *** What is "mitai" It is a broken sound of "MITA-YOU-NA", which consts of "見た（saw/looked), 様(appearance), な". Here you can see the word "様“ is included. **** Gererally "you" sounds more formal than "mitai". It is because "you" is Chinese-oriented(音読み） and "Mita" in "Mitai" is Japanese own word（訓読み）. The imported Chinese words are generally regarded as of formal use. It is like the relation between Latin-originated words and its own words in English.