Ryuuonosuke is the worst character in this manga...followed by Koharu's mother.
Going all the way back to her mom encouraging her into the Hare-kon to help save the cafe, then refusing to even talk to Koharu after Ryuunosuke was verbally abusive to her. She has to know that Koharu is going through a rough time because she hasn't had a baby and Yuzu has, yet she's there making it worse.
I hate the way Koharu's father tried to get her away from Ryuunosuke, but he was right in the end, she should have left the Hare-kon.