Forgot title of this manga

Okay, I forgot the title of this manga BUT I remember a few details from it.

1) Manga is set in school

2) Is about a very smart guy and a very smart girl (Who are in a relationship) in high school (I think) who act perfect like people expect them to, but when they're alone with each other they show a different side of themselves that's completely different from perfect

3) One of the scenes was when the boyfriend put a bracelet of some kind on his girlfriend's leg before kissing her

4) Before that, he was trying to decide whether to get matching cellphone straps or not

5) They're keeping their second faces a secret from others, though one person eventually finds out


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Anyone have any clue?

ya u talking about 14-sai no koi: http://www.batoto.net/comic/_/comics/14-sai-no-koi-r1970

Ah this is it! Thank you!