Yesh,why would you date such a weird,psychopathic woman anyway? You may have millions of bucks but you could find better woman then that,dude. Besides,if you see someone who looks like that at first,watch out!!!
Some is explained, but you're suppose to infer quite a bit. Kazumi felt betrayed because her mother lied to her and resented her because she appeared weak. Kimiko also resented her daughter because she reminded her of the creep. Kazumi loved Kento, but when she found out that he killed her real father, she wasn't sure how to process that. Kazumi is also unstable and isn't exactly sure why she sees Kimiko as the enemy. You can infer that she sees her as competition for Kento's affection and she also complained that Kento leaving was Kimiko's fault.
Thanks. :D