Shiori Minamino is the human mother of Shuichi Minamino (Kurama). She is a very loving mother for her son, as evidenced by Kurama growing attached enough to her emotionally to go to great lengths to ensure her health and safety, such as wishing for her to recover from a serious illness on the Forlorn Hope even though he knew it would take his own life as a price. It it shown in the manga that as a young boy, Kurama falls from a stepstool and Shiori rescues him from crashing to the floor, cutting open her arms on some broken plates as a result. The enduring scars left on Shiori's arms from this awaken Kurama's realization of Shiori's maternal love and he becomes unable to leave her.
During the first few days of his stay in Demon World, Kurama mentions that Shiori had remarried sometime in July of that year (she was actually on a month-long honeymoon for all of August when Kurama had made his trip to Demon World), both her son and Kuwabara in attendance, and gained a step-brother named Suichi (named Kokoda in the English dub), the son of her new husband, a man apparently named Kazuya Hatanaka, who she met while she'd been in the hospital due to her illness.
After Yomi had finally killed the assassin who had failed to kill him (at Kurama's behest) all those years ago, he threatened to kill Shiori by crashing her flight to her honeymoon.