Who do you say good morning dude in Japanese?

The phrase "Good morning, dude" can be translated to Japanese as "おはよう、兄ちゃん" (ohayo, nīchan). This phrase is informal and should only be used with friends or family. A more formal way to say "Good morning" is "おはようございます" (ohayo gozaimasu), which can be used with anyone, regardless of their relationship to you.