I suggest reading Love Triangle first because this is the sequel for it. This story won't really make any sense if you don't read that first. So, This was planned out to be a sequel to Love Triangle (link up there in the blue ^^) but I realized everything I wrote in it

Focused on a group of teenagers 

Sulli's a waitress at a local coffee shop, a girl who is a frequent customer comes in everyday at 6 PM and orders the same thing, always at the same table.