"The Case of Hana & Alice" is a coming-of-age mystery film that centers on the lives of two teenage girls, Tetsuko "Alice" Arisugawa and her classmate, Hana Arai. The story begins when Alice transfers to a new school and becomes intrigued by a local urban legend involving a missing student named Judas, who allegedly had four wives. The rumor suggests that Judas was murdered by one of his wives, and his ghost now haunts the area. Alice, curious and determined, investigates the mystery, which leads her to cross paths with Hana, a reclusive girl who lives next door.

Hana, who was once part of the same class as Judas, becomes an unwilling participant in Alice's investigation. As the two girls delve deeper into the mystery, they uncover layers of misunderstandings, misinterpretations, and personal secrets tied to the Judas legend. The narrative explores their growing friendship, as well as their individual struggles with identity, loneliness, and adolescence. Through their interactions, the story reveals that the Judas legend is rooted in a series of coincidences and miscommunications, rather than any supernatural or criminal events.

The film balances lighthearted moments with introspective themes, capturing the awkwardness and curiosity of teenage life. Alice's energetic and inquisitive nature contrasts with Hana's reserved and cautious demeanor, creating a dynamic partnership. As they piece together the truth, the girls confront their own fears and insecurities, ultimately finding solace in their shared experiences. The resolution of the mystery ties together the threads of the urban legend, providing a satisfying conclusion that emphasizes the importance of communication and understanding in human relationships. The story is a blend of mystery, slice-of-life, and character-driven drama, offering a nuanced portrayal of adolescence and friendship.