looking for Yaoi name

Hey guys, I need your help again..I forgot the name of a yaoi I read some time ago. It pretty much follows a timeline, they first met when they were 17 yo I believe. They were both playing this game, where they were only allowed to step on the separation line on the street, kinda like the floor is lava game. It became a ritual to always meet while playing this game because they were following the same line...I actually remember more but for those who became interested I do not want to spoil it as much. And for those who knows this yaoi I think the information above is enough. It really had a bittersweet ending. Thanks for your help!