If the meaning of 'inner turmoil' ever alluded Hatake Kakashi then it was right after he kissed Sakura that he first came to fully experience the term. Why did he kiss her? He really did not know. Well okay, he sort of did know. Seeing Genma hit on her really irked him. What really made that situation worse was that Genma did it knowing full well how he would respond.
What Kakashi was not prepared for was the wave of jealousy that quickly swept through his system when he witnessed the flirtatious exchange. Sure, he new he liked Sakura but he didn't really think he liked her like that.He just figured they were good friends, but when Genma started getting touchy with his favourite pink-haired woman…he realized that well he might like Sakura more then on just 'friendly' terms. Training with her more and more had, in turn, made them closer. He also simultaneously realized that the once 'little girl' had grown up into a quite capable and well, to be perfectly honest, beautiful young woman.
When Kakashi just couldn't stand the sight of 'Konoha's ultimate player' ogling Sakura anymore, he did what he could to tell her how he felt without having to issue the daunting task of speaking how he felt in words. Therefore, he kissed her. However, in the midst of this kiss his thoughts bombarded him. Thoughts about how she was his student, and she was fourteen years younger than he was. He then realized what he was doing was wrong, and it had to stop. He then broke the kiss, leaving Sakura standing in the streets of Konoha in state of utter confusion. What he had not intended as he left was that Sakura would enjoy the kiss, and would want to pursue the kiss.