Hirunaka no Ryuusei

Hirunaka no Ryuusei (ひるなかの流星, Hirunaka no Ryūsei lit. "Daytime Shooting Star") is a manga written and illustrated by Mika Yamamori. It has been serialized in the shōjo manga magazine Margaret since May 2011.

Plot
15-year-old country girl Suzume Yosano has to move to Tokyo to live with her uncle due to her father's transfer. She bumps into a mysterious man who ends up taking her to her uncle's place after she gets lost. Turns out, Suzume will be seeing him a lot more often once she starts school because...he's actually her homeroom teacher!

Official
http://margaret.shueisha.co.jp/story/hirunaka-star.html

Other Sources
https://twitter.com/whoknowsmika3

Other Wikis
https://en.wikipedia.org/wiki/Margaret_%28magazine%29