If you live in japan and your 16 what grade are you in?

Question:

Just wanted to know...

Answer:

You would be either in the 1st or 2nd year of high school.

If you are 16 today,

If you were born between June 18, 1994 and April 1, 1995, you would be in the 2nd year.
If you were born between April 2, 1995 and June 17, 1995, you would be in the 1st year.