Most species in the family Endomycidae feed on fungi and many are them are colorful (like this particular species), hence the name “handsome fungus beetles.”

Ancylopus pictusAncylopus pictusAncylopus pictusAncylopus pictus

Coleoptera: Endomychidae (“false ladybirds” or “handsome fungus beetles”)
Ancylopus pictus
= yotsuboshi-tentoudamushi (four-spotted false ladybird)