An ink composition having organic pigment particles, a hydrosoluble solvent; a dispersing agent, and water, wherein each of the organic pigment particles has a circularity of 2 nm or less, which is defined as a difference between radii of concentric circumscribing and inscribed circles of a contour of an image of each of the organic pigment particles taken by a transmission electron microscope when a gap between the concentric circumscribing circle and the inscribed circle is least, wherein the inscribed circle has a diameter of from 5 nm to less than 50 nm.