Kitsuki Ikawa

Kitsuki Ikawa was one of Agasha Kitsuki's youngest students and the one who used the word Ninja when describing the secret Scorpion operative developed by the Kami Bayushi and his follower Shosuro.

Ninja
During an attack of black-garbed assassins, he heard the words "Ninja, tori!" ("Ninja, do what I say!"). Thus, he assumed the assassins were called "ninja," a word he had never heard before. However, the words that were actually spoken were "Niwatori," or "Chicken", the nickname Shosuro used for first year apprentices, for the little egg bombs (nageteppo) they were for to carry. Ikawa misheard the phrase and the "ninja" were born.