Higashi no Kurume to Tonari no Meguru

Kousuke has a boring high-school life, but he sits next to his crush—the really popular, cute Tsukahara Meguru, who has a cool, stoic personality. One day, his parents announce that they're moving, but that he'll still be able to attend the same school. The new apartment building has a lovely river and friendly neighbors... and it is next door to where Tsukahara lives! Outside of school, she seems to have a completely different personality, friendly and a little quirky. She makes him promise not to tell the others at school how she acts at home, but why does she put on such an act for her classmates?

(Source: MangaHelpers)