Players assume the role of either Shu (シュウ) or Kizuna (キズナ), male and female Japanese fifth-graders respectively, who have just moved to a new district. After witnessing a luminous object falling into the mountains during a fireworks ceremony, they are transported to the Digital World, where they meet their Digimon partners. They are joined by classmates Hiroyuki (ヒロユキ), a curious troublemaker, and Asuka (アスカ), a caring, older-sister type, along with Hiroyuki's second-grade younger sister Yui (ユイ) and her friend, a first-grader named Takuto (タクト). Together, they must aid their Digimon companions while thwarting a group of villains named Uno, Dos, and Tres.

Source: Wikipedia