a piece of advice from one of brother 1

 "An-chan, an-chan!" Hiro burst into his brother Sakura's room. Before Sakura could even turn around, Hiro grabbed his shoulders from behind and shook him violently. "Hey, An-chan, I need you to listen! I have something to ask you, An-chan! Is there anything you wish you had done after you started middle school? Also, is there anything you wish you hadn't done? What I should've done? You're really asking me that? Me, the guy who failed the entrance exam for my dream university and is now taking a gap year just to study? It's completely obvious!" Sakura twisted his body, shaking off the hands that were gripping his shoulders. "Studying, what else?!"

"So, I just need to get good grades? I've never gotten anything below an A." When Hiro answered calmly, his brother's face immediately turned red. But he soon regained his composure and let out a long, slow breath. "Why did you ask that question?" 

 Hiro explained what his father had told him.  Hearing that, Sakura gave a knowing laugh. "That's a good idea. Most young people just look down on their elders' advice and stories, but you're different."

"I'll listen to you because I respect you. After all, you're the best at setting traps to catch beetles!" Hiro answered cheerfully. "You're in middle school now, so what's with that childish way of thinking?" Sakura laughed with a wry smile, then frowned. "Hold on a minute? If I hadn't been forced to go bug-catching with you that crucial summer before my exams last year, would I have gotten into college?"

"Because it's a rule that kids aren't allowed to go into the mountains alone," Hiro countered. Sakura gave a small shake of his head. "Exactly. And the most important rule in this house is that my brother's safety comes first. I would never blame you for failing to get into college." 

Sakura held up a finger and went on. "That's the reason I'm telling you to study now that you're in middle school. Advanced academics start there, and if you build a solid academic foundation now, it will give you a huge advantage when you choose a university later. You can't just cram and expect to do well when the exams are right around the corner."

Hiro tilted his head. "An-chan, you're still cramming, so does that mean you'll fail the next exam too?" It took Sakura a moment to reply. "…Hiro, it seems you have something to learn before you even think about studying. I was about to break the most important rule of the family myself." 

Suddenly, Sakura clapped his hands right in front of Hiro, startling him and making him take a step back. "Anyway! The one regret I have from middle school is this: I should have studied properly. So, I'm going to go study my butt off now, so leave me alone!"

"Okay, I'll give it a try. Thanks, An-chan!" Hiro said cheerfully. He then left the room, leaving his brother Sakura who was already back at his desk. 

After that, Hiro diligently followed his respected brother's advice. While reviewing everything he had been taught since starting middle school, he discovered that he had often gotten the right answers purely by chance, without fully understanding the reasoning. This realization prompted him to start taking his classes much more seriously.

Hiro also went to the storage shed his father called ‘the stairway to manhood,’ where he found some textbooks for his first year of middle school.

The books, completely untouched, appeared to be the result of a short-lived attempt by one of his older brothers to get back into studying. Without a second thought, Hiro simply accepted them as a convenient find and decided to use them for his own studies.