The Love of Kaoru's Life
Isn't he hot? I can't really blame Kaoru-chan for falling for this gorgeous specimen of a rurouni. But it wasn't Kenshin's looks alone that got Kaoru's heart. It was everything about him, from his sweet, gentle nature, to his protective streak, and down to his oro-ing. I'd like to think that it was love at first sight, but that would be too shallow. I prefer to think that although they were attracted to each other right from the start, the time they spent getting to know each other further deepened their affections for each other. On Kaoru's part, I think it was sort of a school-girl crush/admiration at first (after all, he rescued her from Hiruma Gohei), which developed into a need to have someone by her side (because she doesn't want to be alone), until it deepened into true love. I can't really tell when was the exact moment she fell in love with him because it was a gradual process, but I think that by the time the goodbye episode rolled around, Kaoru was already in too deep.
As for Kenshin, we all know that he was the legendary Hitokiri Battousai. He worked as an assassin for the Ishinshishi in the Bakamatsu. He killed many, many people but an event in his life changed his view regarding life and thus, he spent the next ten years atoning for his crimes. I think that this event in his life made him cautious about getting involved with a woman so he remained a distant air around Kaoru (although, I think he never really fooled anyone). But despite the distant attitude, I think he cared for Kaoru right from the start. I think that at first, he was intrigued by the brave girl who challenged him with nothing but a bokken in hand. Then after she was attacked by Hiruma, his protective streak was awakened. And when it was time to go, he found out that he couldn't walk away from her. And from that point on, it developed into love. I can't really blame him 'cause aside from being beautiful, Kaoru also possessed a pure heart. I think that he was drawn to Kaoru's innocence. After going through so many dark things in his life, I think that he saw Kaoru as the sunlight. For him, in being near Kaoru, he was gaining his own innocence back as well.
To know what I think of Kenshin, please go to the Opinions section!
I'm not planning to write much on Kenshin since there's a lot of shrines out there dedicated to him. You can check them out, in case you're still clueless about him (which I doubt you are!).