"A kindergarten classmate."
Lu Ning listened to him address his peers like he was an old man.
Not 'friend', but 'classmate'.
At the same time, Lu Ning realized something.
When she had found out about the issues about Lu Jingzhi's studies, she was making one-sided decisions on her own without actually consulting him.
"Jingzhi, I want to go to your school tomorrow to talk to your teachers about your studies. If I do, you won't be able to continue in kindergarten and might be transferred to first or second grade, or even a higher grade. All the students there will be older than you.
"Will you be afraid? Would you prefer to stay with your friends?"
Lu Jingzhi looked at Lu Ning. After a long silence, he said, "The kindergarten's full of children, and the teachers ask very simple questions. I didn't want the teachers to treat me like a freak, so I pretended not to know anything and acted like an unintelligent child."