In the beginning of Utawarerumono: Itsuwari no Kamen, a man wakes up in an unfamiliar place surrounded by strange sights. He has no recollection of who he is or where he came from. However, his luck takes a turn when he encounters Kuon, a young girl with animal ears and a tail. She rescues him and leads him back to her hometown while protecting them both from the "boro-gigiri" - giant centipede-like creatures, and an enigmatic red slime. After they arrive, she names him Haku after a famous figure from their region. Haku soon discovers that he is unique among others as he does not possess animal ears or a tail like everyone else in this world.
Later on, Haku and Kuon journey to the capital of Yamato, where they meet new individuals and make friends along the way. As they delve deeper into the politics and internal strife of Yamato, they uncover more about this alien world's secrets. Their mission involves solving the mysteries surrounding red slimes and preventing war from breaking out among neighboring countries. Through it all, Haku works tirelessly to understand his new surroundings and find his place in this strange new world.
Utawarerumono: Itsuwari no Kamen is an adaptation of the visual novel of the same name.Although it came out nearly a decade later, Utawarerumono: Itsuwari no Kamen shares a number of characters and voice actors with the first series, Utawaremono.