She is Black Star's Dark Demon Blade partner. She can change into multiple ninja weapons (shuriken, smoke bomb, a katana [later chapters], etc). She is most of the time disheartened by Black Star's loud self but she still puts up with it because that is what she likes about him. She holds in her a fear that Black Star would abandon her for another weapon (or she might have been over stressing about Soul and Black Star's friendship). She has a very forgiving personality and always tries to help everyone even when she has no idea how to help. Tsubaki soul is "very co-operative and has a lot of space to accept people" as said by Dr. Stein. Tsubaki comes from an established family of weapons descending from a weapon created by Arachne. She also seems to have a talent for cooking, having been complimented on a few occasions by her friends.
Forms:
Scythe Chain: A handheld Scythe at the end of chain.
Shuriken: Large five point ninja throwing star
Smoke Bomb: A bomb for making a smoke screen for escapes or diversions
Dummy Star: Tsubaki assumes the form of Black Star to confuse the enemy
Ninja Blade: A short ninja knife weapon
Demon Blade: The form of her brother's weapon form, a katana (this form drains a lot out of Black Star since it needs a high level of Soul Resonance to be used)
Attacks She has shown the ability to change her hair into a chain or a single scythe chain.
