I think he has started seeing her as a woman post leap not just a sister
Yes, I get you. It would've been even more beautiful if they had properly shown the shift. But I think they started their relationship from the scratch post leap. Arthit being someone who carried strong hatred & grudge for her. He thought she would react the same way & she would be the same brat that turned his life upside down. But suddenly his hatred turned into obsession then softness then slowly into love.
I think he has started seeing her as a woman post leap not just a sister
But once that accident happened he stopped seeing her as a sister. She was just a girl who ruined his life but post leap while bullying her d being around her completely caused him to see her in a new light.
They sooo cuteee
Another kiss tomorrow <3