Thor Odinson is a superhero appearing in American comic books published by Marvel Comics. Created by artist Jack Kirby, writer Stan Lee, and scripter Larry Lieber, the character first appeared in Journey into Mystery #83 (1962) and first received his own title with Thor #126 (1966). Thor is an adaptation of the deity of the same name from Norse mythology, and many aspects of Thor's character are based on Norse myth. Comic books featuring Thor have been published across several volumes since the character's introduction.

Sif is a character appearing in American comic books published by Marvel Comics. Created by Stan Lee and Jack Kirby, the character first appeared in Journey into Mystery #102. She is based on the Norse goddess Sif. As an Asgardian warrior and lover of Thor, Sif often accompanies him into battle. She has also battled alongside Balder, who has developed an unrequited attraction to her, as she never shows affection for anyone but Thor and certain individuals who have proved worthy to wield his hammer, Mjolnir, such as the noble alien warrior Beta Ray Bill, and the mortal Eric Masterson.