@HOOfan_1 It seemed to me more that the MC concerned himself with who was "weak" and "strong" rather than the "right and wrong" in the conflict. His dad was falsely accused, but he still took his own life. So while it might not be clear whether he was just or corrupt, he was definitely weak. MC's own guilt in hurting his father (which he might think drove his dad further to the choice) could result in him trying to protect the weak, whoever that is in a situation, either the bully or the victim. If this is the case, it's a bit stupid (hence why I called it that), but understandable.
Also, who should his Dad have fought back? Only his cowardly self I think. He must have fought the accusers and the accusations in some capacity, otherwise he wouldn't have been cleared of suspicion in the first place.
Regarding the love triangle (which I don't think is the case btw), it'll be explained in the coming chapters anyway so no point in thinking too deep about that. Still, I don't think there was ever an affair, or a framing. They could just have been political partners, and Awayuki's dad just didn't come to help MC's dad when he was in trouble.