The reason why she chose to come back for the military training was because she didn't want to miss the good times of her student life, and the memories that she can forge with her classmates.
"Eh? Ye Jian? Why are you here?" Lu Xin, the class leader, saw Ye Jian as he walked out of the infirmary holding his medicine. She was supposed to be on leave. He smiled with surprise, "Mrs. Tong said that you went to the hospital to take care of your relative and wouldn't be here for the seven days. It's not seven days yet, why are you here?"
Mrs. Tong mentioned it in class before that Ye Jian wouldn't be there for the military training. The other students could accept that since Ye Jian left when they had their evening study sessions previously.
