I decided to conduct the training to expand my vessel by entering a slight 'Demon Eater' state three times a day, just before my mother changes my diaper. This timing is the least uncomfortable.

Even though my body is that of a baby, having "It" in the diaper is unpleasant. Have you ever imagined the feeling of having that stuck to your butt every time you move?

You might say, "Why not do it in the toilet?" but at one year old, I can't do toilet training. I don't know when toilet training usually starts since I've never raised a child, but it's probably around the time a child starts walking, maybe two or three years old.

Until then, I have to get along with this diaper. It's disheartening to think my first friend in this new life is a diaper, but as long as things end well, it's fine. I'll make lots of friends from now on.

"Itsuki, you did a great job expelling your magic today too."

"Majoku! Majoku!"

"That's right. You have to expel it properly, or your tummy will hurt."

As my mother changed my diaper, I clapped my hands. It seems she understands that I'm expelling my magic power. Over the past few days, I've been intentionally expelling it for training, and my mother has visibly become more relaxed.

She must be traumatized by the fact that my brother died from 'Makui.' I understand that feeling.

So, I want my mother to feel at ease. As long as I can expel my magic power outside, 'Makui' won't occur. It simply can't.

Even though I look like this, this is my first act of filial piety.

Actually, seeing my mother relax makes me feel at ease too. Thinking back, I was a kind child when I was little. Where did I go wrong? Well, I'm still a child now.

"How is Itsuki doing?"

"He's much calmer. Recently, he seems to have learned how to expel his magic power outside, so I'm relieved."

"I see. He's learned it on his own. He's a strong boy."

My father lifted me up right after my diaper was changed. I caught a glimpse of my mother's worried face.

"I hope he can safely reach three years old..."

"Yes, indeed. Hopefully, nothing will happen..."

Their voices trailed off, and I inwardly retorted.

Hey! That's what I'm worried about!!

Becoming stronger to avoid dying as an exorcist is a good goal, but if I die before becoming one, it's all for nothing. That's why I'm concerned. What's going to attack me before I turn three?

Not knowing just makes me more anxious.

But I'm no longer just a baby who lies around all day. I'm one year old now. Since I'm one year old, I should just ask.

"Chan-chai?"

I wanted to say "three years old," but my teeth haven't grown in properly, so I couldn't pronounce it well.

Relieved that my training results were real, I couldn't help but smile.

But my mother, looking confused, replied,

"What are you talking about? The total magic power is fixed from birth and doesn't change, no matter what."

"That's true, but..."

My father, with a puzzled expression, hesitated.

So, the amount of magic power doesn't change from birth, huh?

...Then why is my total magic power increasing??

As my father said, my vessel has been gradually growing through daily training. So, it's not wrong to say my total magic power is increasing. What's wrong is the belief that it can't increase.

"Is it just my imagination? No, but... I think it was less when I held him before..."

"Honey, maybe you've been fighting too many 'demons'? You might be tired."

"...Hmm."

My father, looking unconvinced, nodded with a troubled expression.

But I came to a realization.

Maybe the total magic power only grows until the age of three.

In other words, like this:

The vessel grows until the age of three to withstand 'Demon Eater.' But after three, the body adjusts the amount of magic to fit the vessel, preventing 'Demon Eater.' So, the vessel stops growing. The total magic power is measured at age three, after the growth stops. That's why it doesn't increase afterward.

So, people don't know that 'total magic power can increase.'

No, saying it can increase might be incorrect.

If I hadn't discovered I could control my magic power, I wouldn't have thought to intentionally trigger 'Demon Eater' to enlarge my vessel. Regular babies, who haven't developed self-awareness, couldn't do this.

But my total magic power is indeed increasing.

That's all I need to know. Now I just need to continue this.

I stretched my arms to pump myself up.

"Ooh!!!"

"Did he just say 'Papa'!?"

No, I didn't.