The health gauge is the white bar in the upper right corner of the lead character's portrait. Every time he/she takes a hit, their HP (health points) decreases. To restore health, the chracter must run into a Heal Circle or heal themseleves by using certain weapons.
Life Gauge is shown by the five grey squares near the character's portait. If the character's HP decreases all the way to zero, the number of their lives decreases. If the character loses all of their lives, the screen will fade into a Game Over. To restore lives, one must use a certain weapon, or command Mirania to use her Spirit Attack, Revive.