Me, with my allergies, riding that car would be a personal hell I'll never recover from.
I hear that! That is the car of DOOM!
I'm very glad the Prince called Kase out on causing a scene in front of the station on a false premise. I think a lot of the negative reaction to Kase's jealousy stems from how severe her reaction to the Prince was; not the fact that she WAS jealous. I'm hopeful that Kase will take his advice to heart and try to keep herself in check.
While I agree with this in part and don't think Kase should be telling Yamada not to interact with other people, like the Flower Prince, there is another aspect of the problem that was entirely unaddressed: Yamada's inability to communicate with her girlfriend when she is fixated on something.
A large part of the reason that Kase got so out of sorts and upset is that Yamada was consistently unresponsive to her messages on Line and was not answering her phone calls. When you add in the fact that Yamada consistently disregards Kase's concerns that she is too unguarded around guys by stating that she's sure that there aren't any guys who would be interested in her, despite the fact that there have been several who have shown interest across the course of the manga (at the school festival in high school, at the group date in college, at the swimming pool, etc...) it feeds Kase's worry about someone else getting close to her and making a move on her. The whole "wondering if she'd rather be with a guy" thing is probably just Kase's own insecurity because she feels like she was always the more aggressive one in their relationship and Yamada never dated anyone other than her. Now, as readers, we all know that Yamada is head over heels for Kase and that her denials of her own attractiveness stem from her low self-esteem and not any realistic appraisal of how other people view her.
In addition, it turns out that the Flower Prince DID seem to be pursuing Yamada in earlier sections of the story. She had to turn him down when he offered her a ride. He singled her out for attention in their class, even though she perceived it as negative, he probably considered what he was doing as giving her constructive criticism and professional advice. And in this chapter we found out that, low and behold, he WAS pursuing her, but not in any romantic way. He was looking for someone he could trust to pass off some of the extra plants that his (beloved?) boss gave him that he just didn't want to give away to someone who wouldn't take proper care of them. The reason he seemed to be harder on her was probably that he was testing her convictions and wanted to make sure she would stick to her guns and do things her way and not buckle to the way the "expert" told her to do it. However, until he explained everything, it would have been very easy for anyone watching, including Yamada's classmates or Kase if she were following people's posts about things at her school, to interpret it as "The Flower Prince seems interested in Yamada!"
That hell, she is too possessive! let Yamada live her life dammit or better yet trust in her you idiot! hope this incident really let her know how stupid she was acting.
I've always perceived Kase's possessiveness as being driven more by Yamada's naivety and lack of awareness of how pretty she is (due to low self-esteem issues largely). I can understand that getting worse now that they are living about an hour apart and in Tokyo. If just once, Yamada would acknowledge that other people DO find her attractive instead of dismissing it out of hand when Kase expresses concern, then I'd say Kase is entirely out of line. Until then, I really can't blame her for having a pervading feeling of unease about her girlfriend when it comes to how unguarded she is, especially when she is not responding to messages.
So... did anyone else get the distinct impression that the reason the Flower Prince just couldn't get rid of the HUGE amount of plants that Sensei gives him has to do with something similar to why Kase was so jealous? As in... maybe they are dating and that's why he rushed the two girls off the street so quickly when he realized what exactly was going on? (He understands what it is like to be an adult gay person in Japan and wanted to get them in private to talk?)