Momotarou Densetsu is a series of games by Hudson directed by Sakuma Akira with art design by Doi Takayuki that started out as an RPG series in 1987. It was popular enough to spawn several spin-offs and an anime that itself received a further anime spin-off.
It's especially notable for the highly successful spin-off Momotarou Dentetsu, a railway-based digital board game series that has outlived the success of the main series.
The games feature characters inspired by Japanese folk tales and various mythological sources. Each game also almost always have a voyeuristic onsen or bath scene hidden in each game (NSFW) somewhere.
note: not to be confused with Momotarou, the Japanese legend from which Momotarou Densetsu gets its inspiration.
