I know that I don't own Lyoko, but I do own Chen, Grent, Lori, and Tara. Yumi is 15 and Chen is 18. You can figure out everybody else's age when you read.
THAT NIGHT
"Hurry mom. We don't want them to have to take a taxi." Yumi was really excited about her older brother coming back.
"Okay dear. Let's eat dinner first. His plane doesn't land for two hours, so settle down." Yumi could tell that her mother was also excited. They ate their dinner quickly and Yumi made a sign that had her last name on it.
"Remember mom. You stay in the car and I will hold the sign over my face so he won't see me. Aelita, I can't wait for you to meet him. I hope that you are here before we are. If you do get back before us, turn on the porch light. We will do the same if we are back before you."
Yumi washed the dishes and got ready to go. She made a sign for when Chen is coming out of the terminal. They were able to make it to the airport in time to hear that Chen's plane had just landed and Yumi got out of the car and held the sign right in front of her face.
She eventually saw Chen coming out of the airport, and made sure that her face was hidden by the sign.
"Did anyone ask for a car in my name? I know that I didn't," asked Chen.
"None of us did. It must be some sort of prank." A girl had answered.
Yumi spoke without moving the sign. "Gawd, you're still a little mouse."
Yumi moved the sign down to show half of her face. She saw her brother standing right in front of her. The boy looked confused as to held the sign.