The internal structure of the resonant (1405) state is investigated based on meson-baryon coupled-channels chiral dynamics by evaluating density distributions obtained from the form factors of the (1405) state. The form factors are defined as an extension of the ordinary stable particles and are directly evaluated from the currentcoupled meson-baryon scattering amplitude, paying attention to the charge conservation of the probe interactions. For the resonant (1405) state we calculate the density distributions in two ways. One is on the pole position of the (1405) in the complex energy plane, which evaluates the resonant (1405) structure without contamination from nonresonant backgrounds, and another is on the real energy axis around the (1405) resonance energy, which may be achieved in experiments. Using several probe interactions and channel decomposition, we separate the various contributions to the internal structure of the (1405). As a result, we find that the resonant (1405) state is composed of widely spreadK around N , which gives dominant component inside the (1405), with escaping π component. Furthermore, we considerKN bound state without decay channels, with which we can observe the internal structure of the bound state within real numbers. We also study the dependence of the form factors on the binding energy and meson mass. This verifies that the form factor defined through the current-coupled scattering amplitude serves as a natural generalization of the form factor for the resonance state. The relation between the interaction strength and the meson mass shows that the physical kaon mass appears to be within the suitable range to form a molecular bound state with the nucleon through the chiral SU(3) interaction.