[Short Short] The World's Lamest Time Slip

Katsuura burst into the T High School Invention Club, shouting, "I did it!" Yoshino, the club president who had arrived earlier, and Iya, a junior member, both stared at Katsuura.
"I invented a time slip machine!"
"Seriously!"
"That's amazing, senpai!"
With a beaming smile, Katsuura pulled something that looked like a coin case from his pocket.
"It can only handle this size for now, but it's still amazing, right?"
As the two nodded vigorously, he pulled a chocolate coin from his other pocket.
"If you put it in this machine and wait an hour, it returns to its state from five seconds ago."
"Wait, you have to wait an hour?"
"Five seconds ago?"
To the two blank-faced members, Katsuura said, "Just watch," bit into the chocolate coin, and quickly put it into the machine.
After waiting an hour, he opened the case, and the chocolate coin was back to its original state.
"It really did go back! That's amazing! But..."
"Five seconds ago is a pretty high hurdle..."
"Exactly! And while I was struggling to improve it, I didn't have time to study for the test again. Haha!"
A dry laugh echoed. The Invention Club is peaceful again today.
(End - 410 characters)

Good evening. I would like to participate here.

Taraha-san, sorry for the trouble, but I look forward to working with you.
Thank you to everyone who read this.