"... That child has been acting strange lately."

She said in a serious tone of voice.

It's midnight.

The children have gone to bed.

Itosaki Aiko, the full-time housewife of the Itosaki family, sits across from the dining table.

And Itosaki Shōta, the main pillar of the Itosaki family.

The two of them are currently holding an emergency family meeting without the children.

It's about Itosaki Sho, the eldest son of the Itosaki family.

"Sho has been running every morning and afternoon lately. He's been hating exercise since kindergarten, but he's been doing it voluntarily. And that's not all. The day before yesterday, he suddenly said he wanted to buy a textbook. At first, I thought he was just lying to buy toys, but he actually bought the textbooks. I asked him if he bought the wrong one, but he denied it, saying, "No." I was curious if he was really doing the junior high school problems, so I sneaked a look at the textbook last night and found that he was solving the problems.

He's only in the first grade! I can't believe that she can suddenly solve junior high school problems..."

Aiko, in a mixture of upset and confusion, told Shōta what had happened.

Aiko is usually unaware of changes in people, but the day before yesterday, when Sho asked her to buy a textbook for him to solve a problem, she began to notice something unusual about her son.

Shōta, on the other hand...

"It's okay."

He is very optimistic.

"You can't be serious! You're talking about your son! As a father, you should be more concerned!"

His words backfired on Aiko and she yelled at him loudly, even though it was late at night, and grabbed Shōta by the chest and shook him back and forth violently.

She is quick to show her hands when she is angry.

Incidentally, this is also inherited by her eldest daughter Yua.

"Ah, babababa! Ah, calm down, Aiko-san."

"There's no way I can calm down!"

Shōta tried to quiet her down, but she kicked him off with a look full of anger.

"Yes, Sho has changed, that's for sure. That's what I'm feeling, too. I don't think that's a bad thing. If anything, I'm glad that my son is more positive about everything than before."

"That... may be true, though."

Aiko released her grip on his chest as if she understood his words to a certain extent despite her unresolved feelings.

Shōta has a point.

People, not just children, are always growing.

There is a saying that if you don't see a boy for three days, you will see him grow up rapidly. In Sho's case, it was only one day.

Shōta's optimistic view is not because he is taking Sho lightly.

He understands that everyone grows at a different rate, and that's why he says what he does.

"But I'm still worried. It's as if he's become a different person."

Aiko's words also have a point.

Even though each person has their growth speed, Sho's growth speed is too fast and too rapid.

It's as if he's changed.

"I wonder if he has some kind of disease."

"I've never heard of a disease that makes a person suddenly positive..."

"But that's the only way to explain it!"

"Well, maybe so..."

"I don't know what to do..."

"......"

Silence flows.

What they fear more than anything else is that the son they know as Itosaki Sho will disappear if this continues.

This anxiety smoldered not only in Aiko's mind, but also in Shōta's in no small part.

No parent is not worried about their child's situation.

That's why at this moment, they are both worried, and the silence continues.

"... Then, let's find out."

It was the father, Shōta, who started it.

"What do you mean, let's find out?"

"We need to find out if Sho has changed. Once we know some things, you and I should be able to relax."

The uncertainty for both of them depended on the extent of Sho's change.

Whether they know how much Sho has changed or not, the magnitude of their anxiety will vary greatly.

The most unsettling thing of all is that it is unknown.

This is especially true when it comes to son.

"...... Yes, let's do it."

For Aiko, there was a bit of guilt in confirming that her son was indeed the son she knew.

It was the same as not believing in the existence of her son.

――But it was more frightening for her to keep doubting whether her son was her real son or not.

Hence the decision.

"Then we'll take Sho tomorrow and find out."

Tomorrow is the day.

On that day, Sho will be tested. He will be tested to see if he is the real him.