I don't know why, but somehow Watanuki reminds me of Sanji and Doumeki reminds me of Zoro from One Piece.

I've thought of these similarities so far: Watanuki is a good at cooking, Watanuki expresses his like for Himawari very extravagantly (like Sanji for Nami), and Watanuki doesn't like Doumeki, even though they're good friends. It probably is just me, but Watanuki and Doumeki sort of look like Sanji and Zoro too.

So, I'm hoping that I'm not alone here in thinking that.

your right they act the same.