"I DON'T CARE IF I GET TRAMPLED TO DEATH!! I WON'T LET THE REINS GO THIS TIME!!!"
Hachiken refusing to accept his payment in episode 8 after he forgets to connect the milk hose to the tank, causing about 40,000 yen (about $380) worth of milk to literally go down the drain. While Aki's family tells him not to worry about it, he begins to feel really bad about it, due to having cost them some of their livelihood. Despite that however, they tell him to accept the money, because despite the little accident, which they're all only human and prone to mistakes every now and again, they still appreciated the hard work he's put in over the summer break.
Hachiken works himself so hard for weeks that he collapses just before the school festival. Nobody visits him in the hospital except the principal, his homeroom teacher, and his parents (with his father apparently there just to criticize him more). He gets out, fearing his friends have abandoned him and even resent him for not fulfilling all the obligations he took on for the festival... when his friends just couldn't get to the hospital during visiting hours, and between all the work he already did and his incredibly detailed itinerary, they were all able to finish what he started so none of his work went to waste. Hachiken's friends subsequently dragged him to the post-cleanup parties and did their best to share with him a little of what he missed.
The final half of Episode 21, where Aki confronts her family about the fact that she doesn't want to take over the farm, but instead wishes to work with horses. This works for multiple reasons. One, Hachiken goes with Aki to provide moral support, also giving her the courage to finally confront her family about her true dream. At the same time, while her family is indeed shocked, their reaction is also heartwarming. Instead of immediately shooting the idea down or demanding that she take over the farm due to some type of responsibility, the entire family goes back and forth with one another, and with Aki, covering the pros and cons of the paths available to her. This allows them to move from their shock to slowly formulating a plan for Aki's new future, which includes not only the field she'll work in, but a possible place for her to work at, the university she'll attend, and the study plan that she'll use to get into the university. In the end, the entire family fully supports her and her desire to step out of the business they have worked in for generations. Her father's speech near the end really clinches it:
Goushi Mikage: Aki, if you were going to carry on the ranch, I could teach you about this job or how to survive in this business, but if you're going into a different field, I can't teach you anything. I only know farming. All I can do is to figure out how to pay your tuition. If you're serious about your dream, give it a try. Whether you can make your dream come true or not, do not betray friends who support your beliefs.
Komaba shoveling out the bullpen in midwinter and finally practicing his pitch again after dropping out.
Later in the series he finally gets back in touch with Hachiken in order to get under the tutelage of Shingo so that he can get back into school.
In chapter 109, Hachiken's father not (intentionally) meeting Yuugo during Yezo's celebrations. He knows that his presence during Yezo's celebrations would hurt his son, because he would automatically tell him that he expected better.
Earlier before that when he realizes that Hachiken has been setting aside his own money in order to raise the funds to start his own business, his dad smiles for the first time in series.