Sakura and the Yokai Vortex

Ren froze, the communicator vibrating in his hand like a beating heart. Dr. Sato's voice, clear as the water in the pool, echoed in the chamber, defying logic and distance. Yumi and Kiko watched him with a mixture of curiosity and amazement, not understanding the nature of the strange object that emitted the voice of the invisible man.
"Dr. Sato," Ren said with a trembling voice, "is that you?"
A tense silence fell over the cave. The seconds stretched like an eternity as Ren waited for an answer. Finally, Dr. Sato's voice came again, with a tone of relief and surprise.
"Ren! It's you! Thank heavens! I can't believe it works... Can you hear me well?"
Ren swallowed, still unable to grasp the situation. "How is this possible? Where are you?"
"I'm... well, it's complicated to explain. Let's just say I'm in a... different place. The important thing is that I can communicate with you. Are you okay? Where's Aiko?"
"I'm in the Shadowlands," Ren replied, "with Yumi and Kiko. Aiko... Aiko was kidnapped by a yokai."
A gasp was heard from the other side of the communicator. "Oh no! I knew something was wrong. Ren, you have to find her. That yokai... is dangerous."
"Do you know who it is?" Ren asked with a glimmer of hope.
"Yes," Dr. Sato replied gravely. "His name is Tengu. He is a powerful and cruel yokai. You must be very careful, Ren. Wait... did you say with Yumi and Kiko? Who are they? Are they yokai too?"
"Yes, Dr. Sato," Ren replied. "Kiko is a Kitsune, and Yumi is a demon hunter. They have helped me a lot since I got here."
"Incredible!" exclaimed Dr. Sato with obvious surprise. "A Kitsune and a demon hunter... I can't believe you befriended them. You always knew how to connect with people, Ren, but this is truly amazing."
Yumi, who had been listening attentively to the conversation, stepped forward. "Tengu?" she said with concern. "That name... it's a legend among the inhabitants of the Shadowlands. He is said to be a ruthless being who feeds on the fear of others."
Kiko, with her fox ears, approached Ren and rubbed her head against his leg, as if sensing the threat posed by the yokai Tengu.
"Dr. Sato," Ren said with determination, "we will find Aiko. I won't let that yokai hurt her."
"I trust you, Ren," Dr. Sato replied. "I will send you all the information I can about Tengu. Meanwhile, be alert and don't trust anyone. And please, Ren, take care of yourself. And take care of Yumi and Kiko too."
The communication cut off abruptly, leaving Ren with a mixture of hope and worry. On the one hand, knowing that Dr. Sato was okay and that he could communicate with him was a relief. On the other hand, the threat of Tengu loomed over them like a dark shadow.
Ren put the communicator back in his pocket and looked at Yumi and Kiko. "We have to find Aiko," he said firmly. "And now we know what we're up against."
Yumi nodded with determination. "I will help you, Ren. Together, we will defeat Tengu and rescue your sister."
Kiko barked in agreement, ready to face any danger alongside her friends. With a renewed sense of purpose, the three of them ventured deeper into the Shadowlands, determined to defy the shadows and rescue Aiko from the clutches of the yokai Tengu.