In Edo-period documents, the word 与太郎 is used to refer to a fool.
That man's story is complete nonsense.
Yotaro (rakugo character)
A stock character in rakugo, often portrayed as a well-meaning but simple-minded young man. The name is used as a proper noun in this context.
See also: 落語
In rakugo, 'Yotaro' is known for his simple and cheerful personality.
The exact origin is uncertain. The kanji 与 (give) and 太郎 (common male name suffix) may have been used phonetically or as a generic name for a foolish character, later becoming a rakugo stock character.