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Hirota Ishigami was a genius.
Anyone who met him knew it.
At five years old, he could already rattle off the periodic table, solve complex equations in his head, and understand scientific principles that most adults struggled with. He wasn’t just smart—he was exceptional. And he knew it.
People told him all the time how much he took after his father, the greatest scientist in the world. Hirota wore that praise like a badge of honor.
After all, he had inherited his intelligence from Senku.
…Not from his mother.
Hirota loved his mom, of course. She was kind, warm, and always knew exactly what to say when he was upset. But she wasn’t a scientist. She didn’t build machines or conduct experiments. She wasn’t like him or Dad.
And that was fine.
Not everyone had to be a genius.
But if that was true, why did Dad look at her the way he did?
Why did he feel so safe whenever she was around?
Why was she so important, even though she wasn’t like them?
It wasn’t until a casual conversation with Kaseki that Hirota started to question things…
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He had been watching the old craftsman work, swinging his legs as he observed the careful way he shaped metal. Hirota respected craftsmanship, even if it wasn’t science the way he saw it.
Hirota had been rattling on about his studies. He knew Kaeski didn’t understand the ‘why’ it worked, rather focusing on the ‘how.’ It was fine. Not everyone was as smart as him. The pool of people who were was limited to his father, Dr. Xeno, and sometimes Uncle Chrome.
“It’s amazing how much Dad knows about everything,” Hirota mused, mostly to himself.
Kaseki chuckled, wiping sweat from his brow. “That Senku sure is a genius, huh?”
“The biggest genius in the world,” Hirota said proudly.
Kaseki nodded. “And your mom?”
Hirota hesitated. “She’s… not like us.”
“Like us?” Kaseki repeated, raising an eyebrow.
“Yeah.” Hirota frowned. “She’s not a scientist or an engineer. She’s just Mom.”
Kaseki hummed, setting his tools down. “You think that means she’s not as important?”
Hirota stiffened. “…She doesn’t really know much.”
“Maybe she doesn’t need to,” Kaseki said with a knowing glint in his eyes.
Hirota didn’t like the way that sounded. It felt like Kaseki was implying something—something Hirota didn’t understand.
And Hirota hated not understanding.
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That night, Hirota sat at the dinner table, staring at his mother as if seeing her for the first time.
She was talking to Senku, laughing about something Hirota wasn’t following. Senku was smirking in that way he always did when he was impressed but didn’t say it outright.
Hirota narrowed his eyes.
“Mom,” he interrupted, “why don’t you ever talk about science?”
His mother blinked, caught off guard. “What?”
“You never explain things like Dad does. You just listen when we talk about cool things.”
Senku smirked behind his cup.
His mother tilted her head, a finger tapping against her chin. “I just have different interests.”
Hirota frowned. That wasn’t an answer.
His mother simply went back to eating, as if the question didn’t bother her. As if it wasn’t important. But Hirota knew it was.
It had to be.
“Don’t you care?” he pressed. “About understanding things the way Dad does?”
His mother paused, setting down her chopsticks. She looked at him carefully, and for the first time, Hirota felt like he was the one being studied.
“I care about understanding you,” she said gently.
Hirota blinked. “But that’s not—” He shook his head, frustrated. “That’s not science.”
Senku smirked again, watching the exchange like an amused spectator. “You sure about that?” he muttered.
Hirota bristled. He hated it when people talked in riddles, especially Dad. He was always so direct about everything—so why was he being vague now?
His mother just smiled. “You know, Hiro, not everything in life can be solved with an equation.”
“That doesn’t make sense,” Hirota argued. “Everything follows rules. Everything has logic.”
His mother hummed in thought, then turned to Senku. “What’s the chemical formula for water?”
“Easy. H₂O,” Senku answered immediately.
She nodded. “And how would you describe the ocean?”
Senku leaned back, arms crossed. “Turbulent. Unpredictable.”
Hirota squinted. “But it’s still water.”
“It is,” his mother agreed. “And yet, just knowing its formula doesn’t mean you understand how it moves.”
Hirota opened his mouth—then hesitated.
That… wasn’t wrong.
His mother reached across the table, brushing his bangs out of his eyes. “Understanding people isn’t like understanding science. It’s not about memorizing facts or solving problems. It’s about listening. Paying attention.”
She tapped a finger lightly against his forehead. “And sometimes, it’s about knowing when to stop thinking and just feel.”
Hirota scrunched up his nose. That sounded… unnecessary. Illogical.
But at the same time, it made his chest feel strange—like something was clicking into place, even if he didn’t understand how.
He glanced at Senku, expecting him to refute her argument. Instead, his father just smirked.
“She’s got a point, you know.”
Hirota crossed his arms. He wasn’t sure he liked this answer.
But for the first time, he wasn’t sure he disliked it, either.
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Hirota didn’t get it.
If being smart was what made people important, then how could someone like his mom—who wasn’t a scientist, who didn’t invent things—be so important to someone as brilliant as Dad?
The thought stuck with him, digging deeper into his brain until it bothered him.
He tried to test her, dropping little facts and asking her complicated questions. She got a few right, but most of the time, she just smiled and said, “I don’t know.”
She didn’t know.
So why did that not matter?
Why was it fine for her to not know things, but if he didn’t, it was a big deal?
Finally, it became too much.
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One evening, as he sat in his parents’ lab watching Senku work, the question burst out of him before he could stop it.
“Dad.” His voice wavered. “Why do you love Mom?”
Senku paused.
His hands stilled over his latest invention, golden eyes flicking toward his son.
Hirota’s chest felt tight. He didn’t understand why he was upset—why this question burned inside him so much.
“She’s not like us,” he said, his voice smaller than before. “She doesn’t know as much as we do. She doesn’t—”
His throat tightened.
Senku set his tools down and crouched in front of Hirota, placing a firm hand on his shoulder.
“Hiro,” he said, and his voice was so calm—so steady—that it made Hirota’s frustration bubble over.
“Why does it not matter if she’s not smart like us?” Hirota demanded, eyes shining. “Why do you—why do I—”
His voice cracked, and suddenly, he felt so small.
Senku was quiet for a moment. Then, carefully, he asked, “Do you love her?”
Hirota hiccupped. “O-Of course I do.”
“Why?”
Hirota froze.
Why?
His hands curled into his sleeves. “Because… because she makes me feel safe.”
Senku hummed. “She makes me feel safe too.”
Hirota swallowed hard.
“She makes you happy,” Senku continued, voice as sure as the laws of physics. “And that’s what matters.”
Senku reached out, ruffling his wild red hair. “Smart people don’t just pick other smart people, Hiro. We pick the people who make our lives better.”
His fingers carded through Hirota’s hair, gentler now. “And she makes my life better. Just like she makes yours better.”
Hirota’s lower lip trembled. He hated crying. He was too old for that.
But the feelings inside him—confusion, frustration, something warmer that he couldn’t quite name—kept pressing against his ribs, tight and overwhelming.
Senku didn’t say anything, just let Hirota process it all. His father wasn’t the type to offer meaningless reassurances. He gave answers when there were answers to give. But this—this wasn’t a question with a single, logical solution.
Hirota clenched his fists in his sleeves. “But… if it’s not about being smart, then what is it about?” His voice was quieter now, less demanding, more uncertain.
Senku exhaled, thoughtful. “It’s about who you want to be around. Who makes your life better just by existing in it.”
Hirota swallowed. “But that’s not… measurable.”
Senku chuckled, ruffling his son’s wild white hair again. “Not everything has to be.”
Hirota shut his eyes, the warmth of his father’s touch grounding him. His mind was still whirring, trying to analyze, to categorize—but some part of him felt the answer before he could put it into words.
His mother made things make sense, even when they didn’t make sense.
His hands curled tighter into his sleeves. “I thought… I thought being like you was the most important thing.”
Senku’s expression softened. “Being smart is great. But it’s not the only thing that matters.”
Hirota sniffled, his mind racing to keep up.
“But you’re so—so smart,” he choked out. “You could have anyone.”
Senku tilted his head, a rare softness in his expression. “And I chose her.”
Hirota’s breath hitched.
Senku reached out, gentler now, threading his fingers through Hirota’s hair. “Smart people don’t just pick other smart people, Hiro. We pick the people who make our lives better.”
His fingers carded through Hirota’s hair, light and reassuring. “And she makes my life better. Just like she makes yours better.”
Hirota’s lower lip trembled again. He didn’t want to cry. He really, really didn’t.
But still—
“…Mama,” he whispered.
Senku smiled.
It had been a while since Hirota had called her that.
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Hirota sat beside his father in the lab long after their conversation had ended. Senku had gone back to working on his latest invention, but Hirota couldn’t bring himself to move. His thoughts felt tangled, looping over and over again.
He understood now—at least, he thought he did. His mom was important, even if she wasn’t a scientist. She made their lives better. She made him better. That truth sat in his chest, solid and undeniable.
So why did he still feel so uneasy?
Senku didn’t look up from his work when he spoke. “You’re still thinking about it.”
Hirota tensed. “I just…” He hesitated, gripping the fabric of his sleeves. “I don’t know how to talk to her about it.”
Senku finally turned, raising an eyebrow. “Why not?”
“Because,” Hirota muttered, staring at his feet. “What if she’s upset?”
Senku snorted. “At you? For what?”
Hirota scowled. “For—for not understanding sooner.”
Senku let out a quiet hum, considering him for a moment. Then he leaned forward, resting his arms on his knees. “You think she’s been waiting this whole time for you to figure this out?”
Hirota nodded hesitantly.
Senku shook his head. “She wasn’t. She didn’t need you to understand. She just needed you to love her.”
Hirota sucked in a breath.
Senku’s voice softened. “And you already do.”
Hirota clenched his fists. It was stupid—he’d never been afraid of admitting when he was wrong. That was just part of learning. But this felt different. It felt personal.
His father gave him a knowing look. “Go to her, Hiro.”
Hirota swallowed. “But what do I say?”
Senku smirked. “You’ll figure it out.”
Hirota bit his lip, then nodded.
He slid off the stool and padded out of the lab, his heart pounding louder with every step toward the house.
When he finally found her, she was curled up on the couch with a book, eyes scanning the pages. He recognized the cover, it was a present from his father. But this was the first time he got a chance to look at the back. Marine biology? He never knew she was interested in that sort of thing. He liked marine biology too...oh.
She looked up when he hesitated in the doorway. “Hiro?” she called gently, setting her book down.
Hirota’s throat felt tight again.
He took a shaky breath, then moved toward her, hesitating only for a second before curling up beside her.
She blinked in surprise. “Hiro?”
He hesitated, then tucked his face against her side.
“I love you, Mama,” he mumbled.
She didn’t ask why.
She just wrapped him up in her arms, pressing a kiss to the top of his head. “I love you too, baby.”
And just like that, everything made sense.