I am working of a narrative of events leading to the battle of Sekigahara (1600). I am starting my account of events with the assassination of Oda Nobunaga (1582).  Oichi's daughters play roles in events leading up to the campaign and in  the campaign itself.  However, I feel I must explain the details of the loss of their father, mother and step-father.  My goal is to use their case as an example of marriage politics in Japan's Warring States Era at an early stage in the narrative.  Any suggestions about relevant sources would be greatly appreciated.

Thank you.