The right greeting is less about the clock than the relationship.
Japanese greetings, or 挨拶 (aisatsu · greeting), look simple on paper. In real life they are tiny signals: how close you are, whether you have already seen someone today, and what kind of interaction is about to happen. You do not need a perfect rulebook. You need a small set of phrases and the confidence to use them.
The four greetings that cover most days
おはよう (ohayou · good morning) literally belongs to the morning, but the social meaning is broader. Coworkers may say ohayou when starting an afternoon or evening shift because it is their first greeting of the workday. With friends, the casual ohayou is fine. In a workplace, ohayou gozaimasu is the safer polite form.
こんにちは (konnichiwa · hello) is the neutral daytime greeting. It sounds a little more formal than “hi,” which is why friends often skip it and say a name, genki? (“doing well?”), or nothing at all. Use it with shop staff, neighbors, teachers, and people you are meeting in a semi-formal setting.
こんばんは (konbanwa · good evening) works from late afternoon into the evening. Unlike English “good night,” it is a greeting, not a farewell. When you are leaving, say oyasumi nasai only if the other person is going to sleep or you are in a home-like setting.
Meeting someone for the first time
The standard pair is hajimemashite and yoroshiku onegaishimasu. 初めまして (hajimemashite · nice to meet you) means “this is the first time,” so it belongs at the beginning of an introduction. Then give your name: Alex desu or the more formal Alex to moushimasu.
よろしくお願いします (yoroshiku onegaishimasu · please treat me well) has no single English translation. It asks for goodwill in the relationship that is beginning. You will hear it after introductions, before someone helps you, and when starting a project. Do not translate it mechanically every time; hear it as “I look forward to working with you” or “thanks in advance,” depending on context.
Greetings are not a performance
Visitors sometimes bow so deeply and so often that the greeting becomes theatrical. A small nod, eye contact, and a clear voice are enough in most casual situations. Japanese people also do not greet every stranger on a train. Greeting the person you are interacting with matters more than broadcasting politeness to the room.
At a shop, irasshaimase is said by the staff; you do not need to answer with the same word. A smile, a nod, or arigatou gozaimasu when you leave is natural. That tiny exchange is the useful lesson: greetings are invitations to make the next moment comfortable.
Sources & further reading
Listen to the greeting that starts an interaction and the one that closes it. Irasshaimase welcomes you into a shop; arigatou gozaimasu sends you out with thanks. At work, the same people may use ohayou gozaimasu at the start of a shift and otsukaresama desu when leaving. These pairs show that Japanese greetings organise transitions, not just times of day.
Japanese-language sources — what Japanese readers read about this, not what's written for visitors.
I write Honne Japan — honest notes on Japanese living, the real thing behind the polite face. One small, un-aesthetic idea each week: Honne Japan on Substack →.