Krystal was panicking.  Ye-jin's teacher had called her and said a man came by and had picked her up. The teacher had allowed it because Ye-jin said that she knew him. She regretted going to get a change of clothes. It had already been 20 minutes since she had received the call and Ye-jin was nowhere to be found. 

"Ye-jin! Kim Ye-jin!"

She yelled throughout the streets and parks. After 15 minutes, there was still no answer and sign of Ye-jin. Krystal sat down at a convenience store and pulled out her phone to call the police. 

"Ahjussi! This ice cream is really good!"

Krystal looked up. In front of her eyes was Ye-jin and Kai. 

"YAH! KIM YE-JIN!"

Ye-jin and Kai looked up, startled. Krystal ran up to them.

"Mom! How did you come here?" 

"I've been looking for you for more than half an hour. What did I tell you? Never leave from school with anyone except for me!"

"B-but Ahjussi came and-"

"I took her. Don't yell at her. She's already scared." Kai said. 

Krystal slapped him on the cheek. Ye-jin screamed. Kai clenched his teeth. "How dare you. You have no right at all to take her." 

Ye-jin started crying. "Mom, why are you hitting him? What did ahjussi do wrong?"

"Be quiet Ye-jin!" she shouted. 

Ye-jin continued to cry. Krystal put covered Ye-jin's ears and glared at Kai. "Get out of our lives, right now. You're creating so much more work for us. If you chose to leave 5 years ago, take the responsibility of that decision. You cannot just come back like this." 

Kai sighed and looked at the ground.

She uncovered Ye-jin's ears. "Ye-jin, let's go." 

"I-I don't want to! I want to stay with Ahjussi!!"

Kai cleared his throat. "Ye-jin, go with your mom."

"No! I don't want to! She's mean! She hit you ahjussi!" tears streamed down her face.

"It's because I did something I shouldn't have. So, Ye-jin, you should go and do what you're supposed to do. Okay?"

Ye-jin shook her head and continued to cry. Krystal couldn't take it anymore. She picked Ye-jin up and started to walk away from Kai. Ye-jin screamed and held her arms out to Kai.

"Ahjussi! Keep your promise! You said we would meet again last time!! Keep it again!" she cried.

Kai could only frown and watch them go farther and farther away. He could hear Ye-jin scream and cry even after they had turned a corner. 

What had he done?