Left: global dust-to-gas mass ratios vs. global cold gas masses (M_gas ≡ M_H2 + M_H I). Solid circles show galaxies robustly detected in at least one AKARI FIR band and in at least one of H₂ and H I (but observed in both), while downward open triangles show 3σ total upper limits on dust mass for galaxies not robustly detected in any AKARI FIR band. Triangles pointing toward the upper-left show global cold gas upper limits (i.e. the sums of the 3σ upper limits on the global H I and H₂ masses) and are formally all global dust-to-gas mass ratio lower limits. Triangles pointing toward the bottom-right show H₂ masses only and are formally all global dust-to-gas mass ratio upper limits and global cold gas mass lower limits. Right: global dust-to-gas mass ratios vs. global H₂-to-H I mass ratios. Solid circles show galaxies robustly detected in at least one AKARI FIR band and in both H₂ and H I, while 3σ H₂ (resp. H I) upper limits are shown as left-pointing (resp. right-pointing) open triangles. Triangles pointing toward the bottom-left (resp. bottom-right) show 3σ H₂ (resp. H I) upper limits for galaxies not robustly detected in any AKARI FIR band and are formally all global dust-to-gas mass ratio upper limits. In both panels, blue and red symbols represent respectively fast- and slow-rotating galaxies, and the black dotted line and grey-shaded regions show respectively the relation of our Galaxy (Draine et al. 2007) and a factor-two spread around it.