Here is an explanation of what the life sim stats do. Main characters get a default of 600 for each attribute while minor characters get a default of 400 for each attribute. With every attribute the higher the number the better. While an attribute isn't being increased it goes down but attributes get increased more qucikly than they go down.
Energy: All tasks take Energy. The lower the relevant stats are the more Energy it takes per hour. If Energy goes below 0 it will decrease Health by how much it went below 0.
Happiness: If a character's Happiness goes too low they will stay indoors all of the time and won't go to work. Health and Energy affect happiness but other things can too. Emotional affects how quickly Happiness drops or picks up.