The main character did not let anyone near him for 15 years, did not open up and did not trust. His allergy is a "protection" from other people. Only with the help of a robot/Gia, he was able to lower that protection.
Riel is a little annoying. I even felt sorry for Yoo Chol when he proposed to Riel to get married, and Riel just ignored it and agreed to date the main character.
I'm burning up with those two morons who were tracking the van.