Digimon: Digital Monsters - Season 1 - Eps 21: Home Away from Home
Tai and Koromon arrive home, where they meet Tai's younger sister, Kari, and also learn that not much time has passed since they were in the Digital World. Later, Tai gets a message from Izzy telling him not to return, and he discovers that Digimon are appearing in the Real World. He concludes that they must return to the Digital World and help their friends. After Koromon Digivolves to Agumon to battle an Ogremon, a portal opens and transports both of them back to the Digital World.
About Digimon: Digital Monsters

Title: Digimon: Digital Monsters
First Air Date: 1999-03-07
Last Air Date: 2001-03-25
Status: Ended
Rating: 8.1/10 (from 845 votes)
Language: JA
Seasons: 2
Total Episodes: 104
Network: Fuji TV
Genres: Animation, Action & Adventure, Sci-Fi & Fantasy, Kids
Production Companies: Toei Animation, Toei Company
Synopsis
While at summer camp, seven kids are transported to a strange digital world. In this new world they make friends with creatures that call themselves Digimon who were born to defend their world from various evil forces.
Cast

Reiko Kiuchi
Daisuke Motomiya (voice)

Megumi Urawa
Iori Hida / Armadimon (voice)

Rio Natsuki
Miyako Inoue (voice)

Hiroaki Hirata
Takeru Takaishi (voice)

Romi Park
Ken Ichijouji / Digimon Kaiser (voice)

Junko Noda
V-mon (voice)

Kae Araki
Hikari Yagami (voice)

Koichi Tochika
Hawkmon (voice)

Miwa Matsumoto
Patamon (voice)

Naozumi Takahashi
Wormmon (voice)