I probably wouldn't have gotten into dating sims if I hadn't already attempted to get into a number of odd, offbeat fandoms. My first truly nerdy fandom (baseball doesn't count!) was NES games, especially RPGs and action/adventure games with puzzles and characters which grew in abilities. I got to experience the first three games in several legendary franchises: Final Fantasy, Dragon Warrior, and Zelda. The common element between them: complex gameplay + story.
By the way, Dragon Power was the de-licensed version of a Famicom game based on Dragon Ball. Back in the pre-Web days of console games, there were a number of games with licenses added or subtracted, and it was sometimes tough to tell. See http://en.wikipedia.org/wiki/Dragon_Power
Back on topic... I *almost* bought Harvest Moon for SNES, and thought about it from time to time. About two years later, I heard about Thousand Arms (which is almost ten years old now...), and gave it a chance. I liked the relationship parts of the game much more than the RPG gameplay, which had lousy combat and a lot of awkward pauses. So I guess that was the beginning for me.
That was the same year that a wise friend gave me a tape of Slayers TV, which lead to me becoming an anime fanboy.
Prior to purchasing a discounted copy of Three Sisters Story, several things happened. First, I read a few reviews at Animetric and Hentai Neko, and browsed through the reviews at Densetsu.com. Second, I got a competent laptop with a modern version of Windows. Third, I decided to give adult anime a chance, because until then, I'd assumed that I'd find it repulsive. But I ended up liking three of the five which I tried. (Can Can Bunny was decent. First Loves [based on Kakyuusei] wasn't bad. And I had a few positive things to say about Buttobi CPU.) The end result: I found Three Sisters intriguing, even though it didn't appeal much to me.
I might have left the world of ren'ai if I hadn't read Kana -Little Sister- the year after that. It helped me to realize that hey, this weird little genre could be thoughtful and interesting.
Since then, I've become something of a shoujo advocate. I'm weary of boy x girls harem stories, and I'd like to see something else. Yo-Jin-Bo wasn't perfect, but it was a start. So when people start talking about it, I say "MOAR!"










