Formal:
* Sayonara (さよなら): This is the most common and formal way to say goodbye. It's suitable for most situations, even if you don't know the person well.
* O-genki de (お元気で): This means "stay well" and is a polite way to say goodbye.
* Mata ne (またね): This literally means "see you again" and is a more casual way to say goodbye.
* Jya ne (じゃね): This is a very casual and informal way to say goodbye, similar to "later" in English.
Informal:
* Mata ashita (また明日): This means "see you tomorrow" and is a casual way to say goodbye to someone you will see again soon.
* Ja mata (じゃあまた): This means "see you later" and is a more casual way to say goodbye.
Other options:
* Itadakimasu (いただきます): This literally means "I receive" and is used before a meal. It's a polite way to say "goodbye" to someone who is about to eat.
* Gochisou sama deshita (ごちそうさまでした): This means "thank you for the meal" and is used after a meal. It's a polite way to say "goodbye" to someone you've shared a meal with.
It's also important to remember that Japanese is a high-context language. The way you say goodbye will depend on the situation and your relationship with the other person. It's best to observe how others are saying goodbye in similar situations and adapt your own speech accordingly.