I have a 12 hours transit at Tokyo International Haneda (HND), Tokyo airport on my way. I don't have to change airports. Do I have to apply for a transit visa? Is there a minimum hours that we can stay in the airport?
If this is single ticket you typically don't need a Visa and the airport is open 24 hours (unless Covid makes a mess again).
However there are always exceptions so I recommend to put your exact details into this form: https://www.iatatravelcentre.com/passport-visa-health-travel-document-requirements.htm
If this a self connection, things are much more complicated and we would need a lot more details to assess this.