Thank Yaoi For Existing

I think I've known yaoi for 5 years. The worst is that I have known it thanks to Attack on titan. Here is the story the most lame but the most stupid especially!
When Facebook was very popular, I spent all my time on it. And I discovered a Facebook page about doujinshi on LevixEren. YOU HAVE TO KNOW THAT I DIDN'T KNOW THE MANGA ! ╮(￣▽￣)╭
I read several doujinshi about this couple and when I wanted to watch the anime, I really believed that what I read was going to happen ! ! Imagine my face when I was watching it with my family next to me ! Σ( ￣□￣||)
At the end I discovered that they were just fanfictions... （/TДT)/
That's when the adventure with Yaoi began.(๑•ㅂ•)و✧

And you, how was your meeting with Yaoi? Was it as "crazy" as mine?

probably not the best description in the title but I'm searching for the name of a manga I read a couple of months ago, about two school boys who play the game walking home from school where you walk along the line of a road marking and if you step off the line accidently you "die", and they walk past each other on the line every day and fall in love, and in later chapters it goes through their entire lives together.

It was SO CUTE and tear-jerk-y, I really really want to read it again. Anyone know what it was called? ;A;