"Sayonara Itsuka" tells the story of a young man named Date who returns to his hometown after a long absence. He visits his family's old home, where he meets a mysterious girl named Itsuka. As they spend more time together, Date learns that Itsuka is not like other girls, and their bond grows stronger with each passing day. The film takes the audience on an emotional journey, exploring themes of love, loss, and the human condition.