Happy Massacre Ending - Chapter 16

I desperately hoped that Mako wouldn’t fall for the obvious manipulation. I can see that it is comforting to have a partner in crime but from his previous actions, he should well be able to keep his emotions in check to go through with this shit. He helped her more than once and the only way she paid him back was by killing his childhood friend two times and manipulating him. I wished this manga had a more sensible protagonist. If either Nee-chan is dead in or that psycho lives in the next 5-10 chapters I am dropping this. I understand that you have to build tensions but building it on so unbelievably bad decision is something I can’t stomach anymore