We construct a Fisher-Kähler information geometry on coadjoint orbits of the unitary group and show how it controls both reversible and irreversible quantum dynamics. Starting from the Bogoliubov-Kubo-Mori information metric on density operators and the Kirillov-Kostant-Souriau symplectic form on fixed-spectrum orbits, we define the Fisher structure B = g^{-1}ω, prove positivity of -B² with an explicit spectral decomposition, and obtain a canonical untwisting to a Kähler triple (h, ω, I). We then derive Fisher-Kähler gradients and Hamiltonian vector fields, reinterpret Frieden's Extreme Physical Information in the UIH framework, prove an exact one-dimensional EPI-to-UIH Fisher identity, study Fisher spectral channels and universal growth exponents, and anchor the construction with strange-metal magnetotransport and optically trapped microsphere data.