[Sangetsu]

In all of my trips to Japan (several), I've never been questioned or detained by immigration or customs. I've never even had my bags looked at, I'm always quickly waved through with a polite bow.

A lot of how you are treated depends on how you are dressed when you arrive. If you are dressed wildly, have lots of facial hair or things like a pierced lip or eyebrow, you can pretty much be guaranteed a questioning by immigration and an inspection from customs. Never talk back to immigration or customs officials, just smile, and do as they ask.

I'm glad you enjoyed your trip though. Things for me are now reversed, I live in Japan, and now have to deal with immigration and customs in my home country, which I have always found to be worse than those in Japan.