She is a young girl who is well-behaved on the outside but rebellious on the inside.
He is a reserved, calm, reticent middle-aged uncle.
There is no purity in the love of middle-aged people, only desolation remains; there is no absolute, only randomness remains.
Originally two parallel lines that did not intersect, it seemed that this love affair, which was as gorgeous as fireworks, had already been destined.