The bad guys are all being so foolish.
Kaya and her mom really think Kudou will pick them after they beat up his fiancee? Even if they beat Miyo into submission, there's no reason for him to marry into a family that disrespected him and kidnapped his fiancee.
And that Tatsuishi old man is just nuts from beginning to end. The real question is why Miyo's dad went along with this farce. No matter how stupid he is, he should know that Kudou is angry with them already and that doing things this forcefully will only make things worse.
Everyone is just so dumb in this series except the leads.