level after living in Japan for a year

This is a common question I know, but I usually just see people asking how far they can get if they start from 0 Japanese (or close to).

I am set to study abroad in Japan for an academic year some time next year. I took 2 years of university Japanese classes, the most recent semester being taught in Japanese with a strict no English rule. So I'm definitely not starting from zero. My uni doesn't go by JLPT levels, but I was told somewhere between N4 and N3 is what people in my class would be.

I wouldn't call myself conversationally fluent at all though. Beyond the basics (directions, weather, etc.) what I can talk about is often dependant on the topic and rarely anything in depth.
Ex: I can talk about how I think the is pretty and that I played it since I was 8. But I can't talk about the smaller details that go into performance or technique.
Ex2: i can talk about being excited to see __ artist in a concert. But I can't talk about what row/section i am or really go into depth about why I like the artist.
All with probably debatable grammar, but nevertheless understandable.

Considering my level how far do you think I'd get conversational wise after studying in Japan for a year? I don't expect myself to become fluent, but hopefully decent. To the extent I can hold convos longer than like 7 minutes fairly comfortably. At least about my interests. The sort of stuff you'd talk about with friends.

Very difficult question as it depends on so many factors. What I can say:
- When I came to Japan in 2015 my level was probably around N4 but I knew more kanji than that
- I entered into a Japanese language school which was 4 h class per day plus 2-3 h of homework every day
- I am a relatively experienced language learner. Being fluent now in 5 languages and speaking an other 3 to a certain level. Ie I know what works for me when studying a new language
- after 6 months I passed N3 without problems
- after 9 months I started working and started using Japanese to some extend at work, but as I wasn�ft busy at all at work , so I went back to school for an other 6-7 months
- I passed N2 after going to school for 15 months.
Since then I am working full time with about 50% of the work being in Japanese but I am not totally fluent and reading is still hard.

Now what does this mean for you, I have no idea. I had school mates who hardly advanced at all and others who were much faster than me.

In my observation It seems to help if you know Chinese or Korean though. (Not my case though)

this is really difficult to answer as it depends on your own individual character and ability, environment, media consumed, etc etc...

I came to Japan in 2014 having just passed the N2 reading and understanding a lot better than I could speak, likely because I didn't have any Japanese friends back then and the school I'd attended didn't have much conversational practice at later levels. (it's nowhere near actually using the language in real life imo anyway)

It's a bit difficult to pinpoint exactly where I was after a year, likely more confident in daily and casual conversation etc... I learnt Mandarin in school but hadn't used it for close to 20 years and I honestly tell you it helps but only to a certain extent; the grammar is completely different. I have seen people from a non-mandarin/korean language background who have excellent Japanese language skills.

Long story short, it's up to you. Attend your classes, learn your grammar and vocabulary then use it in reality. Buy manga/books to read, listen to the radio or watch movies, make friends etc... good luck!