Lives refer to a character's life-count, and coincides with a boss-character's armor. Though each playable-character has a set amount of Lives at the start of every stage, it is possible to receive Extensions by raising the score-count.
If a playable-character is hit by a bullet during Sugar Rush mode, he will be forced out and the Sugar Level will be reset to 0. He will not lose a Life, but due to the loss of sugar, everything around him will move much faster until the Sugar Level is back to 100. If a playable-character is hit by a bullet when he is not in Sugar Rush mode, he will lose one Life, and a layer of clothes will be destroyed as well. The game is over when a playable-character loses all his Lives.
A boss-character's Lives decrease when a playable-character performs an Armor Break to finish off the boss' Attack Pattern, destroying their armor and anything else inside the Magic Circle. The number of armors destroyed will change the story as well as the CGs unlocked.