32-Year-old Xia Chu, a former art student, is now a designer of children's study aids. The teaching aids she designs have to pass five tests - safety testing, age-appropriateness assessment, educational value review, cost control... Every link is a minefield.
Until she took over a teaching aids research and development project for a national research base, the safety standard review expert sent by Party A turned out to be her classmate whom she had a crush on for three years in high school - Gu Yanzhi.
The boy who would help her hold a seat, bring her breakfast, and smile with stars in his eyes is now a cold-faced "safety clause machine", and every design will be marked "unqualified" by him with a red pen.
What she didn't even know was that he didn't even see the love letter she stuffed in the library drawer at the graduation ceremony. For the past thirteen years, he had always thought that she was the one who left without saying goodbye.
