Testing is important

"Hyoudou, your house sure is very large," Yuuki said while floating on the indoor swimming pool. He could take a rest later and wanted to try this pool.

"Catch me, nyaa!" Kuroka swam around the pool.

"Wait, Kuroka!" Le Fay said while riding Fefnir in the pool.

Issei looked at them with speechless expression.

Akeno was sitting on the top of him and asked, "When are you going to rest?"

"After this," Yuuki smiled and said, "Do you love this immoral feeling?"

Akeno flicked his forehead and sat down calmly.

Ophis also floated on the surface of the pool.

"....."

Issei could only sigh looking at them. Here he was nervous since tomorrow there would be a promotion exam yet they were coming to play around in his house.

"I - Issei-san, why don't we go to the pool too?" Asia asked with a smile.

"A - Asia-chan...." Issei nodded and followed her to play in the pool.

Rias looked at everyone and sighed, "There is a promotion exam tomorrow yet..." She looked at them with helpless expression since they were very relaxed. She looked at Issei and said, "Issei, you still haven't learned knowledge about the devil yet. Go back and learn first."

"....." Issei had just taken off his clothes but stopped when he heard her.

"P - Prez....." Issei looked at everyone who was playing in the pool with an envious gaze.

"If you want to fail the exam, then you can go on and continue to play," Rias said.

"...."

"Don't worry, I'll be with you when you're learning," Kiba patted his shoulder and said, "Let's become a middle-ranking demon together, Issei-kun."

"...." Issei wanted to say something but decided to shut his mouth. He sighed and wanted to go to play but he knew that there was something more important to do tomorrow.

Rias looked at Akeno and Koneko, "Akeno. Koneko. I know both of you have learned the knowledge but don't play too much."

"Yes, Prez," Koneko nodded while swimming.

"Ok, Rias," Akeno only smiled and continued to flirt with Yuuki.

"...."

Rias looked at them and felt quite envious somehow. She shook her head and walked back to check her servant's progress in their study.

Xenovia swam toward him and asked, "Yuuki."

"Hmm?" Yuuki looked at her.

"Is Sekibayashi that you have fought before very strong?" Xenovia asked.

"..."

"He was strong. What's wrong?" Yuuki asked.

"I am not sure but Sekibayashi has reminded me of the strongest exorcist in the church," Xenovia said.

"Oh, who?" Yuuki was quite interested in this matter.

"Vasco Strada," Xenovia answered.

Yuuki thought for a while and asked, "Is he a human or an angel?"

"Are you talking about Vasco Strada-sama," Irina suddenly joined this conversation and said, "If you ask whether he is an angel or a human. Then he became human. Michael-sama has asked him to become a member of Brave Saints but he has rejected it since he wants to die as a human."

"Brave Saints?" Yuuki raised his eyebrow.

"It's a reincarnated angel, similar to the Evil Pieces of the Devil," Akeno explained.

Irina nodded and started her explanation about Brave Saints.

The Brave Saints, also known as the Royal Users, are a set of 13 cards used by the Angels to increase their ranks by reincarnating other beings into the Angels. The Brave Saints are based on the Evil Pieces system of the Devils, albeit being based on a suit of playing cards rather than chess.

The Brave Saint system was created after the peace treaty between the Three Factions by copying the Devil's Evil Pieces system and the Fallen Angel's Artificial Sacred Gears technology. This was so that the Angels could increase their numbers since they could no longer depend on God to create new Angels. The Brave Saints, however, are currently only limited to the Seraphs.

Yuuki was wondering whether it was a good choice to turn humans into an angel. He felt that a human that had reincarnated into an angel would become a fallen angel. He looked at Irina and said, "Shidou-san, is it?"

"You can call me Irina," Irina said.

"You have reincarnated into an angel, right?" Yuuki asked.

"Yes, I have been reincarnated by Michael-sama," Irina nodded.

"Then, is it impossible for you to make children in the future since the angel can't taste a forbidden pleasure?" Yuuki asked.

"Forbidden pleasure?" Asia also joined this conversation since it seemed quite interesting.

"It means sex," Akeno answered.

"S - Sex...." They blushed in response when they heard it.

"I - I can't make children...." Irina wasn't sure but he felt quite depressed when she thought about it."

"Don't worry, you can turn into a fallen angel when you want to have children," Azazel also joined their conversation.

Xenovia nodded and said, "Don't worry, Irina. You will become the first reincarnated angel that has turned into a fallen angel later."

"....."

"No! I don't want to become a fallen angel!" Irina shouted but shook her head, "But I also want to make children!" Her mind was complicated and wasn't sure what to do.

"Well, the number of angels is very small," Yuuki said and added, "Then, there might be a chance in the future for the angel to develop a device to make an angel able to have sex but won't turn them into a fallen."

"Hahaha, that's true," Azazel laughed.

"Eh? Is there such a devil Azazel-sensei?" Irina looked at him with a hopeful expression.

Azazel shook his head and said, "There isn't now, but it doesn't mean that isn't one in the future." He looked at Yuuki and said, "You might be able to develop one thought." He knew that Yuuki was very smart since he was able to create a lot of strong items that could even compete with Longinus.

"Me? Develop such a device?" Yuuki thought for a while and said with a serious expression, "Then, I need someone to test the device later with me..."

"....."

"It's to test whether the device is working or not, right? It would be dangerous for an angel to turn into a fallen angel because of the device malfunction," Yuuki said.

Azazel nodded in agreement with a serious expression, "That's true. Testing is very important."

"....."

They had realized that they had two perverts here.