Red Girls: The Legend of the Akakuchibas

From Viz:
When the Outland People abandoned a baby girl on the outskirts of a village, few imagined that she would grow up to marry into the illustrious Akakuchiba family, much less that she would develop clairvoyant abilities and become matriarch of the illustrious ironworking clan. Her daughter shocks the village further by joining a motorcycle gang and becoming a famous manga artist. The Outlander’s granddaughter Toko—well, she’s nobody at all. A nobody worth entrusting with the secret that her grandmother was a murderer.

This is Toko’s story.