And so do Davis and T.K. from season 2 have a common interest - at least that's what Davis thinks. (xD) That's Kari. Davis wants to reach Kari's heart, he seems like he doesn't like T.K. because of her, he's constantly annoyed by the fact, that T.K. and Kari are so good friends. So is Rika, she wants to be the best, she IS one of the best but is she the one? She is the queen but Ryo is the king and he already beat her once. She wants to be better and she's annoyed by him because of that. On the other side there's T.K. He ignores Davis's jealousy, he doesn't care about it. And he probably has more chances with her than Davis. Ryo is very similar. He didn't comment Kazu's opinion about how Rika could never won that tournament if he was there. He beat her and he doesn't seem like he would want to argue about that any longer. He's nice to her, she's the one who always wants to argue. And that's how it is with Davis and T.K. Davis wants to argue (Rika) because of the common interest Kari (TCG) and T.K. ignores that, he acts normally towards Davis. That's the only difference between the cases. T.K. ignores Davis's jealousy attacks and Ryo flirts with that 'wild cat Rika'.
