Kerokko Demetan
English title: Adventures On Rainbow Pond
Japanese title: けろっこデメタン
Alternative titles: Demetan Croaker, The Boy Frog, The Brave Frog, The Brave Frog's Greatest Adventure
Type: TV
Source: Original
Episodes: 39
Status: Finished Airing
Aired: Jan 2, 1973 to Sep 25, 1973
Broadcast: Tuesdays at 19:00 (JST)
Duration: 24 min per ep
Rating: PG - Children
Studios: Tatsunoko Production
Producers: Fuji TV
Licensors: Harmony Gold
Genres: Comedy, Fantasy
Demographics: Kids

Demetan comes from such a poor family that he cannot even go to school in his woodland pond community. However, he has a friend named Ranatan, the lovely, gentle frog girl who is the daughter of the pond's rich ruler. Naturally her father is quite displeased by this relationship and he seeks to break it up. Nevertheless the young frogs continue with courage and confidence, not only to live their own lives but to guide the heartless leopard frog to a sense of justice and generosity. Gradually the pond community responds to their sincerity and joins them in a march toward a bright future. 

(Source: Official Website)