Sometimes I worry about Yamada, I'm not sure how she could so in love with Kase, and yet so very dense. It's almost as if she has utterly no interest in any physical contact with the person she's romantically in a relationship with.
The way she's been portrayed thus far, it's not a lack of interest. She's been portrayed as someone who literally has no idea how people can be intimate beyond kissing. She's not even aware of kissing anything besides the lips. You get the feeling she was raised in a special breeding vat and only allowed to watch the Japanese version of Mr. Rogers.