Sen to Chihiro no Kamikakushi, Momo e no Tegami Recommendations
They both have the same kind of idea; a young girl moving to a new town against her own will while befriending spirits along the way. Both involve saving parent(s).
Both movies have a young girl moving into a new home and meeting with strange supernatural creatures that help them save their parent(s).
Two stories about overly cautious young girls growing up and learning to be brave through their encounters with spirits and mythical creatures. Spirited Away has more of an immersion into the spirit side of things. A Letter to Momo focuses more on the family aspect. But I definitely saw similarities between Momo and Chihiro-- the two protagonists.
Both films show the encounter of the girl with a group of Yokai giving way to an adventure to save the family of both protagonists.
The protagonists have many physical and emotional similarities.
Sen to Chihiro no Kamikakushi - - - Momo and No Tegami
Chihiro Ogino - - - Momo Miyaura