http://manga.animea.net/hana-ni-arashi-chapter-4.1-page-3.html looks cute.. The female character seems soo naive..
Also, I think, there's a manga that the description is just like :-
There's a couple, a girl who is younger than the boy.. The boy is gonna study at a college. But, at the same time, the boy is worried about the girl, who is cute but very stupid and naive..
Is there any manga like this??

It's probably Love Gashapon or any work by the same mangaka. It's a manhua(chinese/taiwanese) though. As for your second request, sorry I don't know.

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Made the set. Credits to Rae from Offrecord who drew Dante in my Avatar.

maybe something by SAKAI Mayu ??

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"It's so warm that, Before the snow has a chance to stick, He melts it for me."

Don't think so. It's 100% by Yan Xi. I've seen her work and read it. It's probably Love Gashapon. It's definitely by her.

EDIT: Found the exact page. Like I said. Story 3 of Love Gashapon. http://www.mangafox.com/manga/love_gashapon/v01/c003/80 .html

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Made the set. Credits to Rae from Offrecord who drew Dante in my Avatar.