this not a law but a custom You must be generous enough to pay back the good service rendered to you by the staff of the restaurant you enjoyed eating at but tipping them is a no-no. They may take it as an insult, so avoid giving tips to any of them. A simple gesture of saying thank you or “Arigatou gozaimasu” will be enough to let them know that you appreciate their food and service. why is it a insult well japan belives any job or service is wroth a price and thats it it woupd be rude to get more than your sevice is wroth also wages are fair and giveing them money is like saying they cant make good wage on own and need your money wich is a big insult so never tip but be thankful and polite and you will be treated good