The pair have become good friends during their time together in Manchester having previously established a relationship playing international football for Argentina.
Otamendi, 29, says the connection was instant and credits Aguero with helping him settle quickly after moving from Valencia in 2015.
“When I arrived, there were plenty of Argentinians, but because Sergio is my age, we understood each other very well,” he said.
“We’ve shared plenty of moments and chats.
“He helped me in adapting to England. It’s obvious we get on pretty well here and with our National team, which is where we used to meet before.
“Then I came and he helped me a lot. He’s very important for the club because of his goals, his records, his presence, and his sense of humour… that’s why he’s someone different."
Aguero recently signed a new one-year contract extension at City, a deal that, if fulfilled, will mean he has spent a decade as a City player.
He is currently the Club’s greatest-ever goalscorer with 207, having won three Premier League titles and three League Cups since his move in 2011.
Otamendi has urged everyone connected to City to enjoy Aguero before he finally calls time on his days at the Etihad.
“He’s very happy,” Nico says. “He’s been a lot of years at the club.
“When City started to be well known he was already here.
“As I said, he’s very important for the club. The fact he’s staying another year here is very important for us.
“We have to enjoy him.”