This is a photo of two Japanese soldiers Etchu Fundoshi (loincloth underwear) wearing their helmets and carrying their Type 38 rifles with backpacks hanging off of the ends. They are also wearing their leather cartridge belts across their upper torsos like a bandolier. In the background there are some other soldiers and possible a mule near a body of water.
The remnants of stickers at the corners of the photo indicate that this was taken from a larger photo album. Without the larger album for context, the soldiers names, unit, and location are difficult to determine. The grass seems more China or Manchuria than a pacific island, but this is only a guess. They might be getting ready to swim or bathe in the river.
Purchased from Vintage Productions at the Pomona Fairgrounds show.