Since the beginning of the game, you will only have 5 hearts of energy (Powerberries in Previous Harvest Moon title). As you progress through the game, you will gain extra energy to help you in you routine farming work.
Extra Energy :
- Can be gained after mining down until level 100. Rowan will appear and surprise that you've made that far and will ask you to rest for the day. Before leaving, Rowan will grant you extra energy.
- After you accomplished 50 or more memories, the next day you wake up, Rowan will ask you to go out as something had happened to the Memories Tree. Villagers will come by and started to remember the memories of your farm. After the event, you will gain yourself an extra energy.