Ni Jieji, a 23-year-old kindergarten teacher, has seen many children screaming and wailing when they first enter school, but the unusual timidity of Xiaolei still surprised him.
Ni found the 5-year-old boy seldom talked with his classmates. In class, he seemed afraid to speak.
"He didn't even dare to ask to leave when he wanted to go to the toilet," Ni recalls.
Xiaolei might be an extreme case. However, Xu Hui, the principal of Haoertong Kindergarten in Shanghai's Pudong New Area, noticed that on the first day of a new school year most of the children crying are boys. Moreover, boys are slower to get integrated into the "small society" of kindergarten than girls.
The so-called "boy crisis" - the claim that boys are becoming physically weaker and emotionally more vulnerable than girls - is starting to worry Chinese teachers and parents.
To boost the masculinity of boys, the Haoertong Kindergarten has developed a gender education programme, becoming the first and only kindergarten in the city to apply gender education to children as young as 5.
"We would like to introduce some of the best traits in men valued by Chinese tradition, such as bravery, the courage to overcome difficulties and the sense of responsibility," Xu said.
"For girls, we hope to cultivate their gentleness, carefulness and grace," she added.