Adult!Soichiro managing to solve a case just before the ceremony of his and Yukino's daughter, Sakura Arima.
As twisted and narcissistic as it is, Yukino managing to fool everyone up until she meets Arima is pretty impressive.
Making her Character Development of finally coming to terms with who she is and that there are people out there who are better than her even more refreshing and beautiful.
Yukino manages to becomes a surgeon (plastic surgeon) after her pregnancy at 15, she continued to study and fulfilled what she wanted to do. Even though it wasn't seen, Yukino being able to do this is nothing short of inspiring.
A small one, but seeing Hiroyuki go Papa Wolf when he discovered that Yukino is pregnant was pretty cool, especially from someone who was mostly used for comic-relief.
Yukino managing to earn respect from Soichiro's bitter Aunt Eiko when the two first meet.
During a fieldtrip, the entire gang is confronted by male students from another school who want to pick up girls. Tensions start rising and Yukino tries to cool the situation down, only to be physically and verbally assaulted. Arima takes absolutely no hesitation and punches the culprit in broad view of their advisor.
Following that, the advisor plays the 'old man with poor vision' card to let Arima off the hook. Not a terribly inspiring action for an educator but the moment is achieved.