Introduced in the game “Dragon Ball FighterZ,” Android 21 is a Bio-Android that has the strength of Earth’s strongest fighters and the intellect of several research geniuses, thanks to their cells being added to her body. However, she’s originally a human woman, whose son becomes the physical inspiration for Android 16. She also admits to conflicted feelings about the scientist who made her into an Android, who’s implied to be the infamous Dr. Gero, aka Android 20.
That’s some pretty major backstory to stick in a video game, especially given its repercussions for 16 and Gero. The game “Dragon Ball Z: Kakarot” even adds another twist by having 21’s human self appear at Capsule Corporation as a researcher during Vegeta’s early days living there. Yet because Android 21 originally only appears in video games, her place in the “Dragon Ball” canon remains mysterious for some time.
“Super Hero,” however, finally provides something of an answer. Early on in the film, when Carmine (a fellow Android) is displaying the family tree of genius Dr. Hedo, a woman named Vomi is listed as Hedo’s grandmother … who just happens to resemble Android 21 to a tee. While it’s unclear if Vomi’s ever turned into a cyborg, the scene otherwise confirms her existence and pre-Android backstory as canon, and clarifies her ties to Gero: namely, that she’s his spouse. The scene also confirms her stated connection to Android 16 in “FighterZ,” as seen below.