As a refresher:
In Japanese, Arnold Schwarzenegger is known as シュワちゃん (Shuwa-chan). Chan! Complete opposite of Winnie the Pooh. So why is it ちゃん this time?
Like Tommy Lee Jones, Arnold Schwarzenegger has done a lot of TV commercials in Japan, mostly for Nissin Cup Noodle and Alinamin V Drink. In the V Drink ads, he plays a fairly silly character and he’s joined by りえちゃん, who addresses him as シュワちゃん.
No doubt these ads popularized the nickname since the ’90s.