Combining "misunderstanding" and "redemption" into the bond of flesh and blood.
At first, looking at Cen Ning's cold attitude towards Cen An, it's really easy to make people feel wronged along with Cen An - it's obviously the first time they meet, so why are they treated as a superfluous existence? Cen Ning's repulsive look was like a shell of ice, and even his eyes were piercing, as if Cen An's appearance was disturbing his established life. But it is this strong sense of alienation that makes people want to explore: What is hidden under this ice shell?
It wasn't until Cen An discovered Cen Ning's "abnormality" little by little that he suddenly realized that that indifference was not his nature. Maybe it was bumping into him muttering to an empty room late at night, maybe it was finding the medicine bottle hidden in his drawer, or... Those unknown things were like a dull knife, slowly cutting through the "hateful" surface. It turns out that his meanness is defense, his alienation is disguise, and the sharpness he shows to the outside world is just self-protection when his heart is in chaos.
The most touching turning point is when Cen An went from being aggrieved and confused at the beginning to approaching cautiously. He no longer cared about his brother's cold face, but began to pay attention to the frequency of his frown and sleepless nights. This transformation from "being hurt" to "wanting to protect" hides the most delicate tenderness - after all, people are connected by blood. Even if there are misunderstandings and barriers, there will always be a moment when you can see the weakness under the other person's armor, and then you can't help but want to hand over an umbrella.
Purpose: technological development, good health