As Mato prepares to go to training camp with her basketball club, Yomi starts to become jealous of Mato's childhood friend, Yuu Kotari. Mato has more dreams involving Black Gold Saw during camp, and at the same time, Saya takes an interest in Yomi. Upon returning to school, the basketball coach, Arata Kohata, discovers the boy she had a crush on had posted her love letter for all to see. She holds back tears in front of the crowd, and ultimately laughs off the incident as if it hardly mattered to her. Kohata visits Saya afterward, but Saya begins acting strangely by taunting Kohata, reminding her that everyone is laughing at her. In the other world, Black Rock Shooter attacks Black Gold Saw's hideout, killing her minions. Simultaneously in the human word, Kohata experiences a sudden pain in her head and falls unconscious in front of Mato.
On the first day of junior high school, Mato Kuroi happens to run into Yomi Takanashi, a shy, withdrawn girl whom she immediately takes an interest in. Mato tries her best to make conversation with Yomi, wanting to befriend her. At first, she is avoided, but the ice breaks when Yomi happens to notice a decorative blue bird attached to Mato's phone, which is from the book "Li'l Birds At Play." Discovering they have a common interest, the two form a strong friendship.
In an alternate universe, the young girls exist as parallel beings, Mato as Black★Rock Shooter, and Yomi as Dead Master. Somehow, what happens in one world seems to have an effect on the other, and unaware of this fact, the girls unknowingly become entangled by the threads of fate.
