Let's start a little backwards, from the second newest game in the series: .hack//G.U.
One theme of .hack//G.U. is pretty generic in story-driven video games: love. Holy Gandhi, though, this dude has quite a harem. In no particular order, an inner-suicidal/outer-bubbly girly girl, a mysterious woman obsessed with an even more mysterious man, an ambitious fighting champion, a little girl/boy split personality, a legendary bisexual, a walking brain with breasts, an altruistic mother-like figure in a kimono, two serial killers, and a cat.
Let's focus on the actual two important characters though: (Continued after the break.)