This TV series was broadcast in the 1970s. The story premise was about a young boy who was being kept away from his birth mother who was of some high rank like a princess or other. It was during the emperors and shogun era of Japan. A sad drama type of series.
In the ending song of the episode it says something about his mother that he calls as Hahayue no. I can't remember if he was being trained for his higher rank life or becoming a monk. But I think his name was kin-san or something like that. The end song was a very sad soft female voice that sung a letter he wrote to his birth mom and ends with his name.