Rock

Rock (ロック, Rokku) is the protagonist of Black★Rock Shooter: Innocent Soul.

History
Rock was a victim of school bullying in her former life; the experience of having lit cigarette burnt on her back traumatized Rock greatly, even in the afterlife. One day, as she was escaping from bullies, one of them caught up with her and pushed her down a flight of stairs. The resulting injury caused her to fall into a coma and she ultimately died bedridden in a hospital.

In the Threshold, where Stagnant Souls filled with grudges and unfulfilled wishes linger, Rock's soul is reprocessed into a Black Star, and she is partnered with Ron as Black Star No. 01451 to battle other Stagnant Souls in the world.

One day in a desolate town, Rock encounters and befriends the siblings Leto and Io, who tell her about Jack and his serial killings that occur every full moon. The brother and sister later fall victim to Jack that night, and while Rock is too late to save them, she finds and defeats Jack at the scene. Her partner Ron then tells the siblings that they are in fact Jack's former victims in their former lives, whose souls are dragged into the Stagnant Soul's illusory town so he can kill them repeatedly for self pleasure. The siblings are saddened by such revelation, but they nevertheless express their joy of reuniting in the Threshold, as well as the brief time they spend together with Rock, which leaves the Black Star slightly startled as they dissipate together along with the town.

Rock and Ron later find a school and its sole student Hanako Nakamura, who gives the two a tour around the place. As Ron suggests leaving the premise after finding no leads on the Stagnant Soul, Hanako reveals her identity as the Stagnant Soul herself and traps both Rock and Ron while giving them a lecture of her own past life. The bullying experience that Hanako suffered resonates with Rock, whose memory has been suppressed, which prompts her to break free into a rage. Rock eventually pacifies Hanako in battle, but she collapses soon after from exhaustion.

When Rock wakes up, she finds herself sharing a bed with Dead. Dead reveals that she is also a Black Star, and she leads Rock to the lowest level of Black Stars' base of operation, where shes releases one of the Stagnant Souls kept in stasis. As the Stagnant Soul releases their energy in the form of fire, Rock becomes greatly distressed by the flame due to the its association with her sealed memories. After consuming the Stagnant Soul, Dead encourages Rock to discover her own past so she can one day claim her soul as well.

Rock and Ron pair up with fellow Black Star Acta and her partner Nico for a mission to take down the Stagnant Soul of a tiger. During battle, Rock sees a glimpse of the tiger's final moment in life as well as its remorse, which causes her to hesitate and become open to attack. Acta saves Rock from the tiger's mauling, but she is later fatally wounded by it when she lets her guard down, believing that the tiger has been subdued. Rock tries to save Acta after defeating the tiger, an act unusual for Black Stars, which leads to Ron accepting that Rock is becoming irreversibly and increasingly emotional. As Acta dies from her wound, her body dissipates while the soul remains, leaving Rock in shock as she realizes that Black Stars also made from former Stagnant Souls.

Still distraught from the recent revelation, Rock wanders around in the Threshold and encounters a singing Stagnant Soul. The Stagnant Soul attacks Rock when she accidentally disrupts her singing, but Rock is unable to fight back due to the fear she develops from previous incidents. She is then rescued by Ram, who tells her to overcome the fear and fight back, or else she would risk becoming a Stagnant Soul one day. Rock proceeds to fight back, but hesitates to land a killing blow as she sees the Stagnant Soul's past and her desire, causing the Stagnant Soul to beat her back. Seeing that Rock is not making apparent progress, Ram decides to intervene again, however Rock insists they should let the Stagnant Soul to sing to the end, who then disappears as the wishes left behind from her former life is finally fulfilled. In the aftermath, Rock states that she wants to find her past self, and while Ram doesn't stop her from doing so, she cautions Rock that should Rock's quest in search for her previous life turns from hope to despair, Rock may end up as a Stagnant Soul.

On the next mission, Rock and Ron investigate another illusory town for Stagnant Soul. There they find an old woman beating her daughter Cecil for a trivial mistake. Rock stops the beating, prompting the mother to leave while Cecil invites Rock to the restaurant where she works as a waitress. However, Cecil is later beaten to death when her mother catches her chatting with Rock instead of working, which triggers a warp in dimension, sending Rock and Ron back at the scene where they first meet Cecil and her mother outside the restaurant. When Rock intervenes again, Cecil's mother grasps her daughter with a transmuted arm and blame her for the situation they are in. Rock and Ron identify Cecil's mother as a Stagnant Soul and proceed to attack, but they are then interrupted by Cecil, who reveals herself as the second Stagnant Soul as well as the host of the illusion. Although Ron advises Rock to kill Cecil despite showing some pity for her, Rock, knowing from their previous conversations that Cecil merely wishes to reconcile with her mother, encourages her to take the first step and give her mother a hug instead. The mother and daughter then finally reconcile, fulfilling their wishes and begin to disappear.