Jean-Jacques Jacquard, a blonde-haired, blue-eyed French student attending school in Japan, holds senior status alongside Kento Yuki. He survives the initial Magical Gate incident, escaping the computer virus that trapped other children. His hobby involves collecting model pirate ships, with a particular focus on galleon figurines. This interest becomes crucial when the galleon-themed Web Knight Garyūn requires a pilot; Jean-Jacques volunteers immediately, joining Kento's mission to fight the virus and rescue the trapped children.

Personality-wise, Jean-Jacques is consistently cheerful and level-headed, maintaining his composure and upbeat demeanor in various situations. He serves as a narrative foil to Kento Yuki. Both were among the first heroic Web Divers who constructed their own G-Controllers, though Jean-Jacques abandoned his after Garyūn began residing in his laptop, while Kento continued using his. Described as a "Nice Guy," Jean-Jacques exhibits stoic traits through his ability to remain upbeat and acts as a "Sensitive Guy" when contrasted with the more temperamental Naoki Asaba.