There wasn 't a day that went by in the last few years that Madara did not envy his brother. Izuna was blessed with one soul mark, only one, and it was very clear what it was. The naginata that ran down his brother 's arm, handle patterned with flowers, could not have more obviously been a tribute to the crazy woman Touka. Touka was a simple creature whose biggest passion in life was the thrill of battle. Her passion was easy to interpret, as was his own brother 's love for family, manifesting itself as a pair of clasped hands on the bottom of Touka 's left foot.