You can go Community → Leaderboard → all time, and find some pretty old accounts. On PC you can see account ID in the URL, the closer to 1 the older the account.
Mine is 1489156, Michael (creator) is 1. I've been on the platform for around 1.3 years. I know some users have been around (still active) for 15+ years. For example @mysticfive.
nostalgic for 平成。。 i like to imagine these 20 year old accounts leading wonderful lives and being fluent in japanese!
i see comments from these accounts in long pinned forum threads and in example sentences.
I'm not sure about fluent. I have studied for nearly over 10 years by now and still have pathetic Japanese (because duolingo taught me nothing. NOTHING when it came to languages) and haven't had much improvement until moving on to renshuu which I am still on Beginner N5 Japanese. (I normally don't scream but I just cannot stand duolingo)
Even though I've used renshuu for a while, proficiency takes years even a few decades in some cases for most and as far as I know, progress is different for everyone. Some learn quicker, some spend more time on learning and also some just give up entirely even though their account would've lasted for 20 years they may not had deleted the account yet.
Also, fluency means lots of different things such as being able to get a job, talking confidently, reading confidently or even just getting N5 for everyday Japanese.
Fluency has lots of meanings (possibly infinite) and is interpreted differently for everyone. My interpretation on fluency may not be your (general your) interpretation of fluency. Sure the dictionary has its own meaning and definition but if you measure the level, it is different to everyone.
edit: also, the level is time spent on renshuu. someone on level 1000 may had only used renshuu for a year while some accounts that are 20 years old like @マイコー 's are only around level 350 (respecting the time they put into developing renshuu as a full time job as the single dev)
I started on Jul 31, 2016. I don't know if that's OG or not.
That would be almost 10 years ago (if math didn't fail me) I cannot say OG but still pretty long and amazing. Maybe we should have awards or merits that are viewable for people who have been on renshuu for 10 years, 20 years etc. without being off renshuu for any longer than 2 consecutive years. (Not studied here and there on random apps that have failed me [looking at duolingo] for 10 years like me. It is unverifiable and people may lie on the internet)
Otherwise I don't know how many OGs are left from 20 years ago but maybe you could be an honorary OG or something. (I'm not the one who makes the rules for status or anything)
