So, Shiikawa didn't know the whole picture and decided on himself what's best, sending Satoko to her home town where she suffered through her mother and idiotic "relationship" with Yashima, while Mashuu did got up with his living conditions but lacking help from family support. Damn I hate that POS...
Satoko was projecting her father on Shiikawa, was having no proper relationship ideas because her family sucked ass, but now realised that she didn't love him back. I mean, they realised what went wrong but he still is a dick, because despite settling it through earlier didn't knew Satoko issues.
Shiikawa also had family issues, but despite knowing them, didn't change much.