<p>Loop current order has long been proposed as an unconventional electronic state arising from spontaneous symmetry breaking through the formation of microscopic electric current loops. The microscopic origin of these currents stems from imaginary hopping terms, conceptualized as an imaginary charge density wave. Despite extensive investigations, particularly in the context of the pseudogap state in high-temperature cuprate superconductors, its existence remains highly controversial. Here we demonstrate site-selective spectroscopic signatures of a pure imaginary charge density wave in the kagome non-magnetic metal CsV₃Sb₅. Nuclear quadrupole resonance spectra reveal anomalous broadening around a characteristic temperature of 120 K, which coincides with the nematic transition well above the real charge density wave order. In a magnetic field, the spectra exhibit antisymmetric lineshapes, demonstrating that this broadening purely originates from magnetic effects rather than from electric quadrupolar effects associated with charge order fluctuations. The observed lineshapes are quantitatively consistent with local fields induced by loop currents, indicating spontaneous time-reversal symmetry breaking. This microscopic evidence of a pure imaginary charge density wave suggests a distinct form of quantum order and extends our understanding of exotic electronic states in quantum materials.</p>