Tyndareōs (English spelling)

Japanese: Tyndareōs（英語表記）Tyndareos

…often seen as a model of brotherly love. Son of Leda, wife of Tyndareōs, King of Sparta, and brother of Helen and Clytemnestra. His father is said to be either Zeus (the Dioscuri means "sons of Zeus") or Tyndareōs. It is also said that Zeus, in the form of a swan, had intercourse with Leda, and that Leda then cohabited with her husband, so that Zeus's seed produced Polydeuces and Helen, and Tyndareōs's seed produced Castor and Clytemnestra.

From [Leda]

In Greek mythology, she was the wife of King Tyndareos of Sparta. She was the mother of two daughters, Helen and Clytemnestra, and two sons, Polydeuces and Castor.

*Some of the terminology that mentions "Tyndareōs" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…しばしば兄弟愛の典型とされる。スパルタ王テュンダレオスTyndareōsの妃レダの子で，ヘレネ，クリュタイムネストラの兄弟。父に関しては，ゼウス(ディオスクロイとは〈ゼウスの息子たち〉の意)とも，テュンダレオスとも，あるいはまた，白鳥の姿に変じたゼウスがレダと交わったあと，レダは夫とも同衾したので，ゼウスの種からはポリュデウケスとヘレネが，テュンダレオスの種からはカストルとクリュタイムネストラが生まれたともされる。…