Just like Aya, Chidori is also another C-genoma. Her tennyo's name is Pallas (as Aya is to Ceres). Her transformation is, however, slightly unique. She can change to her tennyo form at will. Her clothes are always ruined after she changes, as they are of a smaller fit.
With her petite size, she mainly becomes taller, gets bigger breasts, and her hair darkens and grows longer. She also looks more of her real age in this, and takes advantage of the transformation by "ahem"-ing with Yuuhi. She was caught red-handed in the end by Aya.. xD
The most obvious relationship she has is with Yuuhi. She is secretly in love with him. However, her love was one-sided as Yuuhi only has feelings for Aya, the one he loves, but loves Tooya. Their relationship is more of a circle rather than a love triangle. Her wish never came true, as she died to save the one she loves, taking the bullet from the Mikage group instead of Yuuhi. T^T
ATB © Mizuiro