Li Zhi and Xu Mingli grew up together.
In public, he was the well-behaved model student, her polar opposite. In private, he would crack the school bully's head open with a smile, then threaten him with that same smile not to tell anyone. He was a heartless schemer.
Whether in public or private, Li Zhi knew better than to cross him.
Though he had never once raised his voice at her...
And he had indeed looked after her, guided her, and... "educated" her.
At the start of college, Li Zhi got a boyfriend first, hoping to beat Xu Mingli in the race to romance.
Her boyfriend was an athletic guy with an eight-pack, a happy puppy who was far sunnier than Xu Mingli.
The day Li Zhi happily brought her new boyfriend home for dinner, Xu Mingli was there too.
He was still all smiles as he chatted with everyone.
Then, when Li Zhi came out of the bathroom, he blocked her path.
"Do you remember the sex-ed lessons I taught you over the summer?"
Xu Mingli smiled as he brushed the mole on the tip of her ear, making her shiver. "You're delicate and cry easily. If things get uncomfortable with him, come back to me. I'll teach you for free."
[You are the unsolvable riddle I gladly embrace]
A sick-in-the-head childhood friend X A heartless childhood sweetheart
Both are each other's first, both are pure and inexperienced
Aerospace engineer X Teacher
The blurb has been screenshotted.
Theme: Love means being there