Keisū Denkō (電効 計数, Denkō Keisū) is the friend and sidekick of Maiagaru Umō, also known as the Eighth Clarity. The two of them had known each other for five years prior to their escape from the labs Umō was created and Denkō rendered immortal in.
When Denkō was twelve, she and her father were driving when they were involved in a wreck. Her father was killed from the debris, but, though she was comatose, she survived. Because the Pact of Orphans didn't apply to the children of people in the government, she couldn't be killed...so instead her mind was uploaded to "Ellie", a compact super-computer, so that she could live on.