I present the mid-infrared (mid-IR) properties and environments of
red-sequence galaxies within a supercluster in North Ecliptic Pole
(NEP) area at redshift ~0.087, using AKARI NEP-Wide (5.8 deg2) IR
imaging survey in conjunction with ultraviolet-near-IR spectral energy
distributions. Most importantly, such mid-IR flux allows us to trace
not only star formation rate (SFR), but also the presence of
intermediate age populations showing excess emission over the stellar
light in mid-IR. As such, we find that the red-sequence samples do not
only contain passively evolving red early-type galaxies, but also
contaminated with: 1) disk-dominated star-forming galaxies which have
SFRs per unit stellar mass lower than blue-cloud galaxies, and 2)
early-type galaxies showing broad non-stellar emission in mid-IR
compared to normal red early-type galaxies. Those two populations may
represent transition objects between blue spiral galaxies and red
early-type galaxies. We present how those two transition galaxies
depend on their local density and stellar mass, and discuss which
factor is the primary predictor of star formation activity and the
morphological transformation.