Awe. That actually made me a little teary eyed. Lol. Not kidding. Been playing since gc days. Still my fav game. Thx Nintendo for giving me something to obsess over these last 15 years. (Well 13 years for me).
The Animal Crossing wikis are a decent resource for that. Essentially, there's actually three versions of the original game in Japan, two before the overseas release and one after the overseas release. There are differences between then, but they're similar enough and aren't proper sequels really.
15 years??? And I only found out about Animal Crossing in 2013, and got the game in 2015? Wow. I missed a heck of a lot. Then again, a lot did happen to me in the past 15 years. I've played this game every day since I got it, and can't believe there was a time I didn't have this to look forward to after a hard day at work. I love this game, and am looking into continuing my Animal Crossing life with Happy Home Designer.