Ganta asks Senji to train him to better utilize his powers in battle. Later, after Karako is captured trying to save Nagi, Ganta unleashes his new skills during a rescue attempt - but it might already be too late, thanks to Genkaku.

Before he was an inmate at Deadman Wonderland, Senji was a police officer who used his special powers to fight crime. When he encountered a ruthless gang leader with similar abilities, Senji was forced to fight for his life.