
I remember the plot being like this:
- A small black hair boy gets molested on the train and the blonde boy notices it and defends him. Black & Blondie became friends after that and ride the trains together ever since. The Blondie swore to protect Black, only one day a group of men appear on the train and ended up molesting Blonde in front of Black. Black was too afraid to do anything and all he could do was watch Blonde get gang rape.... However towards the end, it was reveal that Black paid a group of men to mess with Blonde, and was the one behind everything.
The small reference to this story was that there was this small comic where the teacher from this story sees Black right next to him on the train and so did Black. The black hair boy look similar to one in this teacher x student story and the teacher was also a blonde like the person Black met. Both showed them thinking, "my partner is better" or something like that.
I been trying to find it but I just couldn't for some reason... Does anyone know where this manga is? If you read this far, thank you!

It's chapter 4 of this
http://www.mangago.zone/read-manga/yajirushi/
Thanks so much for updating!! And ahaha the Nakajima bread (⌒▽⌒)
Eating yourself...