Good on Koji. Yeah, he's lived his life letting others dictate things for him and going with the flow. In part because he is the weakest within the family. Though could argue his powers never developed because accepted his position. But regardless of his flaws, he still stepped up here. While he would certainly be happier with Miyo, I think he's just confirming that Miyo couldn't be happy getting married into his family. Though he may not be thinking that far ahead. In the end he couldn't forgive how his father callously allowed Miyo's situation because it benefited him. At the very least he's refusing to be selfish. Miyo over Kaya for sure. But he cares more about Miyo's happiness than his own. He may not have been the right guy for this situation, but he is a good guy. Hopefully he isn't stuck with Kaya in the end.
And credit to him for not being an idiot. He already lost to his father once. Getting fired up and charging in would just waste his brother helping him out. Instead he makes the hard but necessary choice. Turning to Kiyoka was the best possible move. Not only is that guy powerful enough to get the job done, but he's got some authority. I'm not sure if kidnapping via supernatural powers is technically within his authority to act, but if so...he can bring an army in on this! Otherwise he can just stomp on his own. Though I think at minimum Godo will be going along too.
God Kaya is just utterly pathetic. An absolute fool beyond measure. It's hard to truly express how stupid she is. In part doing this because she realized Koyoka is hot so...yeah. The other part being that she can't accept Miyo being happier than her. But that would happen anyways!? Whatever way things would end up Miyo's happiness would be higher, because Kiyoka would kick her to the curb. He probably will before this is over! Just to get her out of the way.
The really hilarious thing is how small Kaya's worldview is. She thinks this is something her father can dictate
. No clue whatsoever. Obviously part of that is her father refusing to explain things. He doesn't want to reveal how utterly pathetic he is to his daughter and have her realize that he isn't the ruler of the world here
. There is nothing for him to do. He would have been lucky to get any money out of Miyo getting married. At this point he'll be lucky if his family's disgusting behavior isn't brought into the light. Kaya being connected to this kidnapping makes her family responsible. This could get very messy.
At least Miyo did get to do some nice things before...everything went badly.