Shizuka is the mother of Chikage. She is a trained ninja and also the popular author of the mystery novels on Airan Island. She writes under the pen name of Shizumaru.
Shizuka had been married. Her husband was named Kiyomasa, and he was the older brother to Kagami. She developed a love for writing and books as she was trying to court Kiyomasa. She swore to keep the Beniyasha books going in memory of her deceased husband.
Shizuka's Daughter: Chikage
Shizuka has a single child. Chikage is the daughter she bore with her husband, Kiyomasa. Chikage is a rather bookish child, but she has shown a certain level of ninja training when it comes to stealth.
Chikage is also well in the loop about her mother's identity of being the author of the Shizumaru and the disguise of Beniyasha.
Shizuka's Sister: Kokoro
Shizuka has a single twin sibling in her sister Kokoro. Both were trained as ninja, but Kokoro is the only one who remains as a kunoichi after marriage.