After getting two-day rest, Kai and the others went to the school again, lazing around in their room.

Kai had nothing to do other than researching for another sound-based attack or support magic. At first, he wanted to take the Levitating Concept since it could float him in the air. Unfortunately, he couldn't imagine how he used it, considering he was a close-range fighter.

If he was a Sniper, Gunner, or Archer, he could shoot his enemy down from the sky. With how he fought in close combat, he needed to move around a lot. Meanwhile, the Levitating Concept didn't work because the concept required two plates.

"You are researching again?" Michelle sat down beside him. On the other side, Tasha was also researching something, so she didn't pay attention to him and Michelle.

"Yeah. What about you?" Kai nodded before asking her back.

"Training my shadow." Michelle pointed to the shadow behind her. The shadow was massaging her shoulder like a human with fluid and precise movement. "I need to have perfect control of one shadow first before moving into two and so on. In the last war, I realized that my control wasn't good enough. It might be enough to move around in the open field with a few basic movements. However, the intelligent Magical Beasts made me think otherwise. If I can fight alongside my shadow, I can build up a group of myself. My current target is five shadows with fluid movement."

Kai nodded and turned back to his own research. All of them had their own share of works, including Sanae, who needed to make an assignment for the class. Kai told her that he could see what kind of assignment he made, so he thought it would be better to make it in her own office.

To his surprise, Sanae only answered him with, "It's peaceful here, and I can drink or laze around. I don't even need to put on a facade as a good teacher."

The statement perplexed him since he thought Sanae was a special teacher who loved lazing around. However, she said because she was still in the trial period, the teacher contract could be terminated at any time, so she needed to put up a facade for a while.

At that time, Kai's poker face turned into a smile, laughing at this silly matter. In the end, Kai let her do what she wanted. The assignment wasn't hard to begin with, so even with or without a sneak peek, it was done in a matter of minutes.

"By the way, are you going to get another magic concept?" Michelle asked while looking at the research paper.

"It's Sound Levitation," Kai answered nonchalantly.

"Levitation?" The word of Levitation piqued Michelle's curiosity. It looked like Kai wanted to fly in the sky, so he researched this. After all, there were five members in their group, but the only person who could fly was Ayaka. If they jumped off the helicopter, only Ayaka and one other person would be ready in combat.

It would be a different case if Kai learned flying ability. They would be able to jump and join the fight right after since all of them would be able to leave the helicopter. Of course, Evan wasn't in the calculation because he was a healer.

"It's nothing useful from what I see. I have tried to twist some concepts to make it useful in battle, but I don't have high hope." Kai shook his head in disappointment.

"What do you mean?"

Kai didn't answer her immediately. Instead, he made two magic circles in front of him. The magic circle was spherical, albeit the two were split into half and opposed each other.

"This magic required two magic circles. The bottom magic circle takes the role of a transducer, a vibrating surface that makes a sound. In contrast, the top magic circle takes the role of a reflector. A sound wave travels away from the transducers and bounces off the reflector. This condition allows the reflecting wave to help to suspend objects in midair."

Kai put on his headphones, as Michelle quickly asked. "Is this going to be loud?"

"For me? Yes."

Michelle only looked at him with condolences.

Before continuing, Kai put another layer of Sound Insulation around his ears. He activated the magic circle before pulling the teacup on the table. His finger dipped inside the tea, wetting his finger.

Michelle was astounded. She thought Kai was going to drink it first before giving a demonstration. At the same time, Tasha, Evan, and Sanae were interested in it too, as they glanced at Kai while doing their own things.

He let the tea droplet fall in the between two magic circles. The surprise came at this time as the tea droplet, which was supposed to fall, floated without any sign of falling.

Astonishment filled all the people in the room. These two magic circles weren't his new magic. It was a magic circle to produce sound, while the other one was a magic circle to reflect the sound wave. His vibration sword magic circle had the concept of these two.

After floating for a while, the magic circle as Kai took off his headphones.

"That's the concept of Levitating Sound in a simple way." Kai sighed.

"Why are you disappointed? Can the magic circle make you float in the air?" Michelle asked.

"No. I set this magic circle to 22 Hz, which is on the edge of human hearing. If I use more frequency, you will hear the loud noise like attending a rock concert. It was super loud to only levitate a little droplet like this. If I want to use it to levitate my body…" Kai didn't continue, but the other realized what would happen.

"I see. Not so promising about the concept, I guess." Michelle made a weird smile.

"That is only the original concept. I think I can tweak some concept and replace it with magic… but there is no promising lead at the moment." Kai sighed.

"I understand the importance of this magic since we have our own helicopter right now, just don't overwork yourself," Michelle advised.

"Yeah. I can use half the concept to soften the falling though. Like I make a magic circle on the ground with enough power to soften our fall. Then we can jump off the helicopter." Kai said before looking down, finding a problem. "But I will also need some catalyst because I wouldn't be able to make a magic circle too far away from me."

"What are you guys talking about? If you want to jump off the helicopter, you can just ask me. I will teleport us together to the ground." Tasha couldn't help but comment.

"You know the answer." Kai shrugged while pointing his finger at Tasha.

Michelle chuckled before grabbing the teacup and replaced it with a new tea.

"Thank you."

After satisfying their curiosity, Sanae and Evan focused back on their job.

Kai also began his research again, but...

Suddenly, his communication device rang. This was not his usual communication device, but the device that Sanae gave in the hospital. She said that this device was connected to another device, which was supposed to be in Sakura's hand.

He had been refraining from communicating with her because the situation there wasn't stabilized yet. That was why when he received a message from her, Kai frowned his eyebrows, wondering if the message was a good one or not.

"Ya. It's already a decade since our last meeting… Maybe not since we have met in the school. Unfortunately, at that time, you didn't realize my identity, so it's such a shame. On the other hand, if you see this message, I am sure you know my identity already from a certain person.

"Though I want to talk to you, I am afraid I can't. Firstly, after a few months, the situation in United Asia has calmed down. Because of the loss of both sides, there are many daily reports about deaths in the News. In the end, Tokyo has become a disruptive city, and many start leaving the city. Even the school is suspended there.

"The situation turns into a cold war between the north and south with Tokyo as the epicenter. Don't worry, I am safe here, and there is no possibility of a big scale war happening soon… or at least for around six months.

"That's why if you are reading this, enjoy your life at the moment. After everything is fine, I will go to your place and meet you. Although I miss you, it's better we meet after the peace comes to this land once again. At that time, let me have some private time with you.

"PS: I will try to send once a month, and please don't reply to this message. Even though the situation has calmed down a bit, I still need to be careful."

Kai fell into silence, staring at the message. This might be the first time he heard the word of Sakura or Yajima Haruko after a decade.

Michelle noticed his expression and peeked at the message. "Oh. The way this message talks looks like Sakura."

"Yeah. This is the communication device that Teacher Sanae gave me." Kai nodded while glancing at Sanae.

"It's good then. At least she is safe. We can meet her in the future, so no big deal. After all, if the situation turns chaotic, the other families from each prefecture wouldn't look at this in a good way and might band together to stop the war," Michelle said.

"Indeed." Kai nodded before looking at the ceiling. He muttered inwardly, 'Take care.'