Harue deciding that she will try again at being a pro, but only after helping to guide the girls she's coaching to victory. It's nice that she overcame her past trauma while still remaining loyal to her charges, disproving their fears that she was planning to leave them or saw them as a means to an end.
Yuu mentally expressing her intention to get back all the points Kuro lost, declaring that while her younger sister has always protected her, this time, it's her turn to step up.
Harue's reaction to the team clearing the semifinals, succeeding where she failed.
Harue: (thinking) The barrier I could not overcome in my time... because I lost here. (speaking) I... All this time, I was worried whether I could be sincere... celebrating when you win. But now... (cries Tears of Joy) all I feel is happiness... way beyond my own matters! Congratulations everyone! Thank you.
After Arata understands why Harue stayed away from mahjong for so long, and the fact that she's coming to help coach them in order to overcome her past trauma, she, while getting dressed in the morning, puts aside her uniforms ribbon and puts on Harue's necktie instead. The entire sequence happens without any words, making it subtly yet effectively done.
When going in for her semi-finals match, Harue asks Arata if she thinks her necktie will be bad luck, but Arata reaffirms her desire to take it with her as she takes the championship.
The reunion between the Achiga girls and Nodoka, where Nodoka immediately remembers Shizuno, Ako and Kuro, and they both express their resolve to meet again in the finals. Not much is said, but it's clear that not much needed to be said in that case.
Nodoka's smile after seeing her friends from Achiga clear the semi-finals.
Kumiko: (telling Nishida about Nodoka leaving) She said thanks and told me to say she was sorry. And... she somehow seemed to be in high spirits.