When Kurogane gives Syaoran the mashed bananas laced with painkillers as apology "Don't act like your life doesn't matter to me". It's especially important since at that the rest of group still actively shunned Syaoran.
When Fai confronts Syaoran about his drinking problem, it shows that Fai is getting over his anger toward Syaoran in order to help him.
When Kurogane cuddles with Syaoran for the first time since his kidnapping, finally admitting to himself that he loves Syaoran.
When Kurogane forgoes his pride and straight up confesses his love for Syaoran and admits to being scared of losing him after the disastrous Chess Finals.
When Kurogane gives Syaoran his jacket after Syaoran was nearly ran over by a car.
Despite getting temporary amnesia, Kurogane regains his memory by looking at Syaoran.
Fai and Syaoran finally making amends.
The kimono-fitting scene. Syaoran is trying out different kimonos and he finds one that he and Kurogane definitely like.