The film "Doraemon: Nobita and the Castle of the Undersea Devil" does not feature any identifiable LGBTQ+ characters or themes. Its narrative focuses on childhood adventure and science fiction elements, resulting in no depiction of queer identity within its story.

The film "Doraemon: Nobita and the Castle of the Undersea Devil" does not feature any identifiable transsexual characters or themes. The narrative focuses on an undersea adventure with established characters and does not touch upon gender identity or transition.

The film features Shizuka, the primary female character, who participates in the adventure but does not engage in or win direct physical combat against male opponents. Victories against antagonists are typically achieved through the use of Doraemon's gadgets or group efforts, not individual physical prowess from Shizuka.

The film features the established main characters of the Doraemon franchise, whose genders remain consistent with their canonical portrayals. New characters introduced in this specific movie do not constitute gender swaps as they lack prior canonical gender definitions.

The film is an animated adaptation of the Doraemon manga, featuring characters consistently depicted as Japanese. There are no instances where a character canonically established as one race is portrayed as a different race.