It's a story about a small business owner in China who received a strange call and flew to Japan to take care of his inexplicably extra brother.
"... I am your brother."
"Huh? Why has no one told me this kind of thing? When did I have a brother like you?"
"Brother."
"Hey, hey, hey, don't scream, little kid."
"... I am already sixteen years old."
"·····"