“Reindeer Beetle” is not the official name of this click beetle, but my kids thought it was the best name! The male uses these huge feathery antennae for detecting females. I found two males today in two different places, so this is obviously their season. I found a female beetle last June (see here).
Coleoptera: Elateridae (click beetles)
Pectocera fortunei = hige-kometsuki
Location: Edge of a field near Genkai New Town (google map)