In the case of mixed-valence system whose spin states are situated in the spin crossover region, new types of conjugated phenomena coupled with spin and charge are expected. From this viewpoint, we have investigated the multifunctional properties coupled with spin, charge and photon for the organic-inorganic hybrid system, A[Fe^IIFe^III(dto)₃] (A = (n-C_nH_2n+1)₄N, spiropyran; dto = C₂O₂S₂) by means of the magnetic susceptibility and ⁵⁷Fe Mössbauer spectroscopy. In (n-C_nH_2n+1)₄N[Fe^IIFe^III(dto)₃], in addition to the ferromagnetic transition, a new type of phase transition called charge transfer phase transition (CTPT) takes place around 120 K, where the thermally induced charge transfer between Fe^II and Fe^III occurs reversibly. The charge transfer phase transition and the ferromagnetic transition for (n-C_nH_2n+1)₄N[Fe^IIFe^III(dto)₃] remarkably depend on the size of intercalated cation. In the case of (SP) [Fe^IIFe^III(dto)₃] (SP = spiropyran), the photoinduced isomerization of SP under UV irradiation induces the charge transfer phase transition in the [Fe^IIFe^III(dto)₃] layer and the remarkable change of the ferromagnetic transition temperature.