When you have got the ball into the hole and the applause sound plays, press all the buttons on the controller. At least on the Japanese version (which is the one I own), the words “SPORTS MIZUMO” will appear on the score screen. What’s that about?

Wow… I bet that Mizumo is an alternate spelling for Mizuno, and therefore, you likely found a hidden advertisement for Mizuno Corp., a sportswear and sports equipment manufacturer that has headquarters in both Japan and the USA, which appropriately makes a lot of golf equipment.

Could also be the golfer’s name….

sw201444 wrote:
Could also be the golfer’s name….

No, as the string is hardcoded in the ROM.

BTW, you only have to press Select.