@turbotime, true. Kan does seem like a big foil to Miwa. Also seeing a character bully another character out of jealousy and not turn it over the top is pretty amazing.
Kan is a big dick, presumably a dick loving dick, but I think he finally figured himself out. His meanness towards Miwa seems to stem from him internalizing that "being different is bad", and since no one's been shitting on Miwa, he went ahead and did it on his own.
It's a big slap for both of them. Miwa's bazongled into realizing some people can have problems towards her (which could be a prereq to her realizing other people can have problems with themselves). While Kan got to do all his self reflection jizz and try to explain to himself the bad events that happened in his past.