What do you mean, like an old friend?

The meaning of this sentence is as follows:

People dressed in blue came from the drizzle as if they were old friends.

Analysis:

Blue, that is, Tsing Yi, can be translated into blue clothes; A misty rain guest can be translated into a person from a slight drizzle; It can be translated as if it were, as if it were; Old friends refer to old friends, old friends, that is, people who have known each other before; Come can be translated as come and come.

The word "misty rain" indicates the scene at this time. There is drizzle in the sky and smoke in the distance, creating a misty atmosphere and giving people a melancholy feeling. The whole sentence expresses the author's longing and expectation for the old friend, as well as his own faint melancholy, like a hazy rain.