If you're looking for anime similar to Lily to Kaeru to (Otouto), you might like these titles.
A bratty girl named Mia is given a book, Thumbelina, which upon reading she is shrunk and transported into the world of the book. She embarks on a journey to return home, and to normal size making friends and learning lessons on the way, but that's only the beginning of her adventures.
Mia is a young girl with a knack of getting herself into trouble. One night, her mother falls asleep while reading "Thumbelina" to her, Mia is magically transformed into the two-inch tall character. As she journeys through "the Unknown Country of Wonderland," Mia will be forced to overcome obstacles that helps her grow into a person.
When otherworldy Kazumi met normal Yuko at a rockin' punk show, great things were destined to happen. And great things, of course, implies riding a cybernetic creature from the TV named Face to another world full of scantily clad heavyweight men, encountering murderous and sex starved jello-like demons, and even gaining the ability to morph body parts into weapons! Just a normal day in the life of two friends... right?
Ten frogs set out in search of adventure in their swamp, sailing in a boat made from a running shoe. Based on the children's book by Hisako Madokoro and Michiko Nakagawa, the story of the frogs returned in a second episode, in which they went to a summer festival.
Animated children's story about a nonconformist but brave frog. Bunna wants to challenge his community's status quo by learning about the world outside.
Could little Heymon lead his friends escape from terrors safely? Yet, the journey for seeking the refuge must go on.