We were walking home last night across Zempukujigawa Park. It was around 11 o'clock and the rain had picked up, the river was moving more swiftly than usual, puddles of mud were spreading under the pine trees. In the darkness I noticed a small movement on the path along the river's edge, progressing from the river toward the woods. At first I thought it might be a rodent but it was moving a bit too slowly for a rat in the rain. "It's a frog!" I shouted at last, but, no, it was two frogs, one small frog clinging to a bigger frog's back. They stopped as we approached them, not showing the slightest apprehension (how do frogs show fear?), allowed me to take their picture, then calmly moved on.