>>88654587basic jist is that he was a close friend of PPP and manager for purin/meru/kana. was a huge groomer, extremely controlling mod, and tried to isolate them and turn them against each other. really vile shit like literally ordering them not to talk to each other. kana in particular (who was THE rising star at the time) was driven out of the company by him
and I fully believe that he was kana's biggest anti /here/. left deep scars on all of them for a looong time, and kana's reputation in particular was completely trashed until ember spoke up and confirmed that she was right all along. he eventually got "fired" and is generally believed to have been secretly brought back as "Manager B".
rather than PPP who was just a lazy rich faggot that wanted to passively earn money by doing nothing, S-Train is reviled because he was the type of person who seemed like his entire purpose in life was to actively manipulate girls, crush their dreams, and throw them away. just sadistic and evil. he was by far the biggest detriment to tsunderia's success and he probably would've caused a LOT more damage if it weren't for the near-superhuman efforts of slugma.