Why you can't stand M!Kana?
When compared to F!Kana’s, his personality is a void. F!Kana has deep, relatable fears and worries (supports with Foleo and Shigure), is revealed to be able to outsmart a young adult (supports with Dwyer), has artistic interests (supports with Mitama), is very good at math (supports with Siegbert), while M!Kana is just… mama’s boy who low-key wants to be an adult and gets friendzoned.
(I’m saying “low-key” ‘cause F!Kana shows to be more mature than him, and on multiple occasions in her various supports. She gets a job on her own, delivers things on her own, then goes and buys a ring for her dad with the money SHE earned. She organises a math festival with only the help of Siegbert. She accepts the fact that, despite being Kamui’s daughter, she is not always his priority in a world torned by war. From what I remember, M!Kana just does stuff for the army in his supports with his dad, and not on his own initiative but because of a competition.)
F!Kana’s personality is much more diverse and her fears are very relatable and deep for a character this young, as I find the fact that she’s joyful but feels terribly lonely very interesting. She felt lonely for most of her short life waiting for her dad to come and visit her, so when he finally comes back and gets ATTACKED she becomes so furious she changes into a dragon to protect him. But even now she’s part of the army, her parents are still very busy with their war duties and she can’t spend much time with them, so her loneliness still cripples her… so much that she REGULARLY leaves the camp to hide in a bush and cry discreetly about it (supports with Foleo). Her supports with Shigure, in which she shows a strong dislike of teenagers, hint at her own fear of becoming a teenager: in her head, a teenager is almost an adult, and an adult doesn’t spend time with their parents anymore. And she is gonna become a teenager soon…
She feels like she’s running out of time, time with her dad that she was robbed of because of the Deeprealms (and the war).
So she feels very lonely AND is haunted by the thought of her parents leaving her once she’s a grown up, a stage of her life that is just around the corner… And her parents are so busy dealing with the army and the war that she bottles everything up and doesn’t share her worries with them. “I know you’re busy…”, she says in her My Room lines. This poor dear thinks her parents have better things to do than listening to her rambling.
The fact that she is able to bottle up everything is very impressive (and very mature and selfless for her age), and very tragic as well.
So that’s it, I think F!Kana is a much better, well-developped character than M!Kana, and that’s why I love her and don’t like him ¯\_(ツ)_/¯