Successfully complete the game. Hero mode is activated when you start a new game session; which will overwrite your saved game. In this mode, hearts last half as long, hearts and heart flowers will not appear unless you are carrying a Heart Medal, you will start with a fully powered up Skyward Strike attack, the Sheikah Stone will let you access all the hints, and you will have your previously collected insects and treasures. Additionally, Boss Rush mode will include the final Boss.