Remind me again, who are the crazy ones? This bitch of a sister is cheating on her husband with her manager and imposing her brother's face onto him. If anyone is crazy it's her. And if memory serves, she's also responsible for how most of Hiroto's relationships failed by constantly rejecting any girl who showed interest. And as his wife explained, Hiroto has sacrificed much for his mother and sister. If Hiroto is messed up, it's primarily because of his sister. So not only can she get married and Hiroto supports it, but now she's cheating on her husband, whom she put unrealistic expectations on. (because she looked for characteristics of her brother in other boys, she found an upperclassman who was reliable, but that is high school. The real world doesn't work like that. We all have to settle down and compromise is inevitably). This woman is just selfish. That's all that can be said about her.
Sure, the husband is shown to be too laid back and lax. But I'm sure if he's working crazy hours (as is custom for the Japanese workforce), his mind isn't always going to be operating at 100% capacity. I'm curious to see his point of view. It's crazy how she forces her unrealistic expectations on people, then at the same time, blame her husband for her own bad behavior. I've seen this happen in real life, and it's just disgusting. And those making excuses for what she did are just as deplorable. She's an adult. No one forced her to do any of this. Stop enabling bad behavior, and stop coddling adults who do selfish things simply because they are stressed and didn't expect their lives to turn out how they envisioned as teenagers. That's Life!