If there's one thing that flies by the fastest in this world, it's vacation time.

Time flies, and in the blink of an eye, a new school semester is about to begin.

For Chongzong, Yui Uesugi, Yuki Uesugi, and Mizuo Koga, who have all advanced a grade, this new semester holds special significance.

New school, new classmates, new teachers, new courses – everything is new and full of unknowns.

It fills them with both excitement and nerves.

Yuki and Mizuo bid farewell to their elementary school uniforms (what a pity!), donning their new middle school uniforms (not bad either!) and, accompanied by their older sister Yukino, they step through the gates of their new school together.

On the other hand, Chongzong and Yui Uesugi, now in high school uniforms, enter their new school with the guidance of Uesugi Tano.

In Japan, the first day of school and graduation are important milestones in a child's growth. Parents must accompany their children and take photos at the school gates to keep the memories alive.

Unfortunately, Yuki Mizuo and Chongzong Yui's school years start on the same day, leaving the parents with no choice but to split up and attend different schools with each child.

Fortunately, Yuki and Mizuo are in the same school, while Chongzong and Yui also made it to the same high school, making it more manageable.

As for what happens after their enrollment, the Uesugis have full confidence in these four children and are not worried at all about their adaptability.

Similarly, the children themselves do not anticipate any insurmountable challenges but are rather eager for the new environment.

Despite their anticipation, the first day of this new school year seems never-ending.

Although Yuki and Mizuo are in the same school, they are placed in different classes – Yuki in Class B and Mizuo in Class D.

After reaching the first-year floor, they have to part ways temporarily.

"Stay strong, Yuki." (Mizuo)

At the parting moment, Mizuo holds Yuki's hand tightly in a melodramatic gesture.

"Don't worry, you have to stay strong too~" (Yuki)

Yuki is used to Mizuo's antics and remains unfazed.

"See you later~" (Yuki)

"Yeah, see you later!" (Mizuo)

After bidding farewell, they enter their respective classrooms.

They smoothly integrate with their new classmates, some of whom they knew from elementary school and are now in the same middle school.

Then, the homeroom teacher conducts an introduction about the school and the courses, guiding everyone through the enrollment procedures.

Everything goes smoothly until Yuki and Mizuo leave together and arrive at the shoe lockers on the first floor.

At the entrance of every school in Japan, there are shoe lockers for changing shoes, a traditional practice.

Students keep indoor and outdoor shoes separate to maintain cleanliness inside.

As they open their lockers and are about to put on their shoes, a glint of cold light from metal spikes inside the shoes catches their eyes simultaneously.

At first, they couldn't believe their eyes as they picked up the shoes to examine them.

Once they saw what was inside, both of them froze.

There were nails in the shoes.

It was a common way to bully someone.

But these two harmless little girls, on their first day of school, hadn't picked any fights with anyone. How could this happen to them?

Quick-witted Mizuo looked around immediately.

The person behind this bullying or mischief must be lurking nearby, watching them in the hope of seeing them step on the nails.

Despite the hustle and bustle around them, Mizuo didn't spot anyone suspicious.

"Forget it, Mizuo, maybe it was a case of mistaken identity." (Yuki)

Yuki gently tugged on Mizuo's hand, not wanting to escalate the situation.

But Mizuo was already furious, her face turning bright red.

"No, I need to get to the bottom of this!" (Mizuo)