手糸 == keito == woolen yarn
糸電話 == itodenwa == telephone made from two tin cans and a piece of string
This character originated in a pictograph of a skein of yarn. Henshall
suggests as a mnemonic: 'Skeins of twisted thread.'
For extra credit: in which episode of Utena does an 糸電話 appear? Who is using it? What does it symbolize? What color is the string? Why is it that color?