Ironically, the tennis part of the series isn't what keeps me interested (most of it goes right over my head.) It's the characters I love, and anytime I can see them interact outside of the court is a bonus. I didn't read the manga until I was mostly done with the anime, so I can't say that the manga influenced my addiction very much (I still enjoy it, though.)

I love Fudomine and their background story. Kippei is such a great leader, and I enjoy seeing how he relates to the other boys. I confess a special love for Akira and Shinji (I can never remember the others' names. *guilt*)

Kaidoh wasn't a big fave at the beginning, but he grew on me pretty quickly. As for my thoughts on Inui's intentions with Kaidoh, I'm not sure that belongs in this kind of post. XD

I actually really loved that scene with Tezuka and Kippei, especially with everyone saying that Fudomine were supposed to be so brutish, there's the captain being very polite (and earlier, as well, when he introduced himself.)