Standard disclaimer here.
Her face is beset by wrinkles—tiny ravines in her skin that remind her of her mortality—taunting her with murmurs or what could have been; what she could have had.
She wonders at the fact that she has never really felt old, even though she has seen over half a century in years and remembers every last wretched detail. Never has she called herself a grandmother or acted as if she were, but prefers rather the idea of being an older sister and a friend. After all, she is not her teacher and does not like to have her age thrown back at her.
So she wakes in the morning, and, with a simple gesture—simple because she has had decades to practice it—her wrinkles disappear into smooth, young skin. No longer is she a crone of sixty, but a young woman who has not yet had time in her life to lose a brother, and a lover, and a teammate to insanity.
She is just Tsunade, and she is an immortal, smooth face carved into stone.