I spent a few years in Tokyo as a kid and went back most summers to stay at my grandparents' house too. My mom spoke it to me growing up and then in the US sent me to Japanese school on Saturdays so I was forced to maintain it (bitterly..though obviously I'm glad now). I can read hiragana, katakana, and some kanji. Now I have this strange somewhat childish conversational fluency but I've re-learned/learned a ton in the last year. My Japanese agent speaks some English but not that much, which is perfect for working on both her English and my Japanese.