are you kidding, the game is practically based upon the love story
take ion mind htat I havent played 3-6, but I'd say 7's was the most complicated, by a long shot in fact, You have Tifa, clouds old childhood friend that cloud seems to not notice that she likes him, and then Aeris who cloud ends up kind of falling for, but there's different turnouts for who he likes throughout the game, you can even end going on a date with yuffie, which I never expirienced.
But yes, it wasn't necessarily complicated, but more confusing that the others. 9 didn't have much of a love story at all. 10 had a love story but it was more basic than 8's. 12 I still havent completed so I cant speak for it.