Gaara was not afraid of Naruto and he wasn't excited. He certainly isn't in love with Naruto. The reason he looked like that is very simple and has already been hinted at but to be safe I'll put it in spoiler form.


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<span style='color:#D6DBE0'>As time goes on during the chuunin exam Gaara is slowly loosing control of his demon. As he watches the fights he is becoming more unstable as Shukaku gains more influence over his vessel a.k.a. Gaara.</span>



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