JSFiddle - React, Tailwind, and code Playground

HTML

<input id="username" type="text" value="Default" />
<input id="password" type="text" value="Default" />

JavaScript

$('#username,#password').focus(function(){
  if(!$(this).data('seen')) {
    $(this).data('seen',true);
    $(this).val('');
  }
});