Aguero is popularly known as Kun. He got the nickname as a boy growing up in Quilmes, Argentina, when his grandparents spotted his resemblance to one of the young Aguero's favourite tv characters, a Japanese anime character Kum Kum. Kum Kum was the star of an early classic series from the legendary Sunrise Inc studios and was a 'naughty prehistoric boy'. He was also known as Kum Kum The Menace.
As Aguero explained in an interview with the BBC in 2008, he was responsible for changing the name to the shorter and snappier Kun.
"Kun actually represents a Japanese cartoon character from my favourite series that I used to watch as a child. I coined the nickname Kun because of my resemblance to the character, who was actually named Kum Kum. My grandparents were the first ones who gave me the name. I think my nickname is different in comparison to most athletes and so I have grown to appreciate it because it's unique. It's not everyday an athlete is nicknamed after a cartoon character!"