I have an old (1996) felony conviction in Japan and am barred from visiting: Can I transit through there?

In 1996 I was convicted of felony importation of 23 grams of pot. I served 23 days in jail and paid a $11000 fine and had 30 days to leave the country. In 2018 I tried to go back on my way to China and Vietnam. I was detained at the Narita airport, held incommunicado for 18 hours, and put on the same plane I came in on, back to Portland, against my will.

I can never visit Japan again. But, can I transit through there, on my way to Hanoi, without getting jerked out of line and being sent back again? We're scheduled to leave on the 15th of April, so time is of the essence on this answer.

Thanks for any help.