Sometimes I'll say shit in Japanese that you guys don't understand, so here!
Have a little guide for your ass!

Arigato - Thank you
Arigato gozaimasu - Thank you very much
Gomen'nasai - I'm sorry
Doumo - Has many meanings. Can mean okay, sure, thank you, sorry, etc.
Aishiteru - I love you
Kawaii - Cute, obviously. Everyone knows that.
Konnichiwa - Hello
Ohayoo - Good morning
Oyasumi - Good night
Ja - See you
Sayonara - Goodbye
Kudasai - Please(requesting)
Dozo - Please(offering)
Hai - Yes
Chotto - No
Shirimasen - I don't know/understand

Hope that helps you guys :3

~Aly