Tomo

Kenshiro and his great rivals.

強(と)敵(も)

Tomo (強敵) is a term used several times in Hokuto no Ken by Kenshiro. Usually the word tomo is written as 友 "friend", but in the manga it is written as 強敵, which translates to "a strong rival". So a loose interpretation of it could be interpreted as a "friend through rivalry" or "honorable opponent".