A lot of these kids end up becoming very obsessive as well, which is a trait Meguru has shown in spades. The line between actual romantic feelings and just being so happy someone is showing you kindness for once can get muddled in a hurry for them, in ways that they're just not equipped to deal with.
Honestly, I don't like how Kasane handles Meguru's somber mood (for lack of a better term). Because Kasane could have asked pertinent questions instead of accepting or taking what Meguru asks of her at face value out of fear of offending her crush-- I understand that that's not Kasane's MO so to speak (not her personality) but still, she shows herself as another adult in Meguru's life who's unstable and I can sense deeper and starker problems in the next chapters.
But, I'm aware that we're only 16 chapters in so maybe, the kiss may change Kasane's perception of her and Meguru's dynamic. Maybe Kasane will be more pro-active in trying to set Meguru in the right direction without compromising the romance in the story, unlike Meguru's sister who chose to sweep the tension under the rug.