Japanese news site Sora News 24 reported reaction from locals on social media, quoting one as saying: "Imagine if he came to Japan and introduced himself as a 'chimpo' to officials? I'd love to see their faces!"
Another joked the moniker has "made junior high school boys happy".
In announcing Harry's role, BetterUp CEO Alexi Robichaux said while the prince would not have any direct reports, he would join all-hands meetings and company events.
He said: "It's a meaningful and meaty role."
The app matches people up with life coaches and therapists, a bit like a dating app. Major companies including Google and Facebook use it to support their staff's mental health. The app has been valued at $2.4 billion.
But despite the company's success, Robichaux declined to confirm how much the duke is being paid in his first ever corporate role.
Similar jobs in Silicon Valley companies pay millions of dollars every year, along with bonuses and other perks. Harry's employer also doesn't know what hours he works.
"I'm not worried about hours. I'm worried about contribution and I'm worried about change and positive change."
It's the latest addition to a portfolio of projects for Harry, which includes Netflix shows and a Spotify podcast with wife Meghan Markle.
