The same question has been asked by tinang below :) Check it out :)
Anon, help me please. I've read this manga long time ago. Its about a boy who want a girlfriend if i'm not mistaken. Then, his cousin or stepbrother or something like that, but i don't remember, offer to teach him how. He is actually like the boy and always acting cruel to that boy. I think one of them is in karate club? Its cloudy, me myself can't remember much. If you do know, I'm totally appreciate it. (⊙…⊙ )
Could it be this one? :)
http://www.mangago.me/read-manga/too_close_for_love/
Yes!!! Thanks a lot. Luv you(づ￣ ³￣)づ ~
You're welcome :D
I'm truly delighted you found the manga you're looking for, but the illustration itself is not by Maruya Kae. I love Maruya Kae's style of drawing, which is very beautiful, but the image that comes up when I click on that link is definitely by Sasaki Kumiko.
What manga is this from please?
http://www.mangago.me/read-manga/kimi_ga_iru_basho/mf/v01/c001/41/