Rin-chan wa Suezen Shitai is a Manga/Manhwa/Manhua in english language, ROMANCE series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Kobayashi is a thirty-something high school art teacher, and Rin-chan is the beautiful and popular girl at the school. These two people shouldn't have anything to do with each other, but actually they share a common secret. A reluctant love comedy between a middle-aged teacher and a naively eager JK!