Chihiro encounters the old arachnoid Kamaji and his bizarre army of soot balls who keep the hot water running. Chihiro tries to help, but she's not really suited for this kind of work. When Lin the slug girl comes to deliver lunch, though, Kamaji tells her to take Chihiro with her. Lin introduces Chihiro to the bizarre bathhouse wonderland where she works and to her boss, the giant-size matriarch Yu-baba.

After a demonstration of her powers, Yu-baba renames Chihiro "Sen" and puts her to work. Sen goes through a grueling first day of scrubbing floors and being made fun of by the other workers for being human, but she forges on. In the middle of the day, while everyone's asleep, she sneaks outside to meet Haku...