Well... I long forgotten most of the grammar/conjugation/tense structure from the semesters I took of Japanese back in college.
Sure Hiragana/Katakana are pretty much in here, locked in almost, some kanji still, but know how to say phrases etc.... naw I'd struggle, I'd have a much easier time just reading a JPN manga, which I have a few of, from back in my college days to help me become familiar with seeing all the characters etc.