Which were in large part consequences of his decisions.
His sisters hate, the bully, stephanie. They all follow the same theme in that what happened with him was because old mc never really bothered to look at the people around him. He was looking entirely at himself, feeling sorry for his unrequited love of cathrine and fleeing into games and porn.
And with that people started to drift away from him. His little sister grew resentfull over his unwillingness to spent any time with her. His older sister became ever more distrustfull towards him. His childhood friend got ever more angry and lashed out stronger and stronger over her unrequited feelings and stephanie, without any support network, fleed herself into debauchery.
That's the major theme of the seduction route here. That mc finally starts to look at the people around him and emphatizes with them. Giving emily the attention she craved, giving stephanie the intimacy and support she desired, emphatizing and helping with alyvia's struggling and finally understanding what made victoria so angry.
It's really rather sad that at this point for the AVN, we have to provide Cliff Notes to help some viewers catch up with plot and character development that has been pretty clearly described and referenced numerous times throughout the story.
It's almost as if people are just looking at the images, and not really reading the words . . .
That said, this is a remarkably concise assessment of the character dynamics at play to this point; with the addition of one final note for clarity:
The MC is an "Ugly Bastard" - a common theme or "plot device" in anime / porn fantasy - and the phrase is used as a description of his attitude and personality at the starting point of the story. But, as the story unfolds, we are told that Jacky married his father when she was still a student (about age 16) and became pregnant with Alyvia soon after.
His father died when he was still quite young, and he doesn't clearly recall much about him (yet), while Emily barely remembers him - so her character also lacks the influence of a clearly defined "Father Figure", and she has lingering resentment over this without really understanding why. This is another aspect of the bond between the MC and Emily as the closest male she knows while growing up.
Final point: MC's father was a talented photographer, but he fully embraced his responsibility to support his growing family - and so he gave up on his dream to establish a studio for his desire to provide a steady income for his family - and after he died, the fact that Jacky never achieved any higher education meant that her earning potential was severely limited, so she had to work long hours at menial jobs, and money was always tight. This is another big motivator for the MC during his "second chance" . . .