I think I found it in an iceberg video somewhere, the story of the song goes that there are 3 friends (Miku, Luka and some other girl), one day Miku and Luka get into an argument, one pushes the other and one of their friendship bracelets falls onto the road. Then the other girl tries to pick it up but she gets hit by a truck (or just a car) and the rest of the song follows the other two as they try to cope with her death. I remember in the MV the spirit of the other girl was actually following them and was only put to rest after they reconciled at the end. I also think JubyPhonic made a cover of it. Any ideas on what it could be?