Yubaba allows her to stay by having her sign a contract . The contract Chihiro signed allowed Yubaba to take Chihiro 's name Kanji , and change her name to Sen. Then she finds a boy named Haku who is really a dragon who befriends and falls in love with Chiriro , their relationship is dangerous to have because dragon spirits are not allowed to talk or have contact near humans .
When Chihiro signs the employment contract , Yubaba takes all of Chihiro 's name except the first character of her first name ( å ) , which Yubaba calls `` Sen. '' Sen later learns that Yubaba controls her servants by taking their names .