No one knows why this falls was named Momotaro.
Momotaro Falls (桃太郎の滝) is one of waterfalls in Shima Onsen. It is located on Lake Shima. Therefore, you can see this waterfalls on the small hiking course around the lake.
Tourist Info.
There is a parking.
Access
0. at Nakanojo Station.
1. use local bust to Shima Onsen.
2. walk south (30 min.)
20 min
New Wave Samurai Movie. 
映画好き集まれ！ 
No one knows why this falls was named Momotaro.