Do you think Gray and Cana could be couple

They seem more like friends to me.

I think so ^-^. Cana always remind to get his clothes but she smiles at him. They known each other for a long time. And when I see Cana, gray's half-naked.

well it's not impossible but i don't think they match. just my opinion.

Cana is not Gray's type,I think.

Yeah I do actually, they have the same personalities, and they fit each other well

Well, it mostly depends on the way you look at it. Cana & Gray were both the only little kids at the guild for quite some time. In flashbacks of the past, Gray & Cana were often seen hanging out together on the benches at the guild. Even after other kids joined Fairy Tail, Gray & Cana were seen around each other a lot because Natsu was often with Lisanna and Mirajane was often arguing with Erza. I think the reason they aren't popularly shipped is because they don't have enough screen time together because Gray is usually fighting with Natsu. Even when they're older, Cana has been seen sitting with Gray at the guild- especially in the first episodes. Cana also doesn't seem to mind Gray's stripping problem like most of the female characters and often points it out to him because she is amused to see his reaction. I personally think his stripping has even rubbed onto Cana a little, considering her usual attire and a scene that occurred in the manga (where Cana slightly stripped a bit). As I already pointed out, Cana is not often seen with Gray because they don't both show up on screen together as much. This is most likely because Cana isn't as important to the series as Gray is. I guess I somewhat ship them, but I don't think they have much of a romantic interest in each other. Cana had a crush on Macao, and Gray just doesn't seem to completely like anybody (though, judging by the recent Fairy Tail episodes/chapters, Gruvia is what Hiro Mashima has in mind). Still, I think it's fair to call Gray and Cana really good friends from the long time they have known each other.