@pants there's one thing that separates this from ACTUAL tragedy porn (Chi no Wadachi , Shounen no Abyss, Henshin Emergence, Kimi ni Aisarete Itakatta)... tragedy porn hasn't sickeningly fluffy and lit moments, neither full blown fluffy chapters (like chapters 13 to 16 in this case), but only relies in depression and pitch black humor. This is just a drama SoL love story, with emphasis on the drama part. Other manga similar to this in the drama sense can be Sakura Tsuushin, Musume no Tomodachi (this one seems to go the tragedy porn route though as of the latest chapters) and in a more toned down and "suitable for children" terms, the vintage "Ie naki ko" (Nobody's child) animu and some of the world masterpiece theater series (in the sense of having comfy chapters and then chapters when things go south, if not directly straight to hell for the main characters).
And MC is just a naive and victim to the circumstances kid, but not pathetic. If he was THAT pathetic, he wouldn't saved the main heroine from her would-be rapists, neither ditching the local bitch amidst of their date and follow his heart and just let the universe decide for his demise.
@HajimeteNHK it's not that two dimensional. Previous chapters already gave quite the depth and information about some characters' reasons to act like they do. Hence why these manga are labeled as seinen, bc you have to read twice or thrice and try to think to fully get the meaning.