This is a story about redemption.
I don't know if he redeemed her habitual pretense, or if she overcame his pretense of being strong.
From the initial misunderstanding and estrangement to the final deep love, she completely surrendered her true feelings, but in exchange, he said: "You don't take it seriously, do you?"
It turns out that in this love game, she slowly began to believe it was true, but he was always sober and calm.
It's just that she doesn't know, it's not that she doesn't love her, it's just that she doesn't dare...