Story about how I got confessed to by a boy I thought of as my friend for 10 years is a Manga/Manhwa/Manhua in english language, SUGGESTIVE 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

The Beginning of... Love!? Straightforward and pure high school love! Rintarou, the boy who've been friends with since we were small. Large, grim and popular. He turned down a girl again... What a waste! "No, because I love you." ...Huh? What!? That's the first time I've heard about this!!! W-w-w-why me- Damn...!!! I can't believe he would confess to me. I feel like I lost and it's frustrating. Now that it's come to this, I'll test him and see if he's good enough to be my boyfriend!! A straightforward and pure high school love, begins!!