Home Away From Home is the title of the 21st Adventure episode.
Tai and Koromon get sucked into a black hole and turn up in Tai's home town. Tai heads home to find no one but his little sister Kari there. Tai gets a message from Izzy on the computer saying, "don't come back." Tai knows he has to get back to help them but doesn't know how to get the digivice to work. A digimon appears, but disappears again and Tai realizes that the real world is in as much danger as the digital world. Tai rushes out to try and find the portal back. Ogremon attacks and Koromon digivolves into Agumon to fight him. The portal opens and Ogremon gets pulled in, same with Agumon. Tai gets ready to be sent back too when Kari grabs his arm to stop him.

Kari: Tai! Stay with me!
Tai: No. Go wait for mom and dad.
Kari: I'm so sorry
Tai: Why?
Kari: You're right, I know you have to leave.
Tai: I really do. ok?
Kari: ok
Tai: Agumon can't digivolve without me.
Tai: This is my fight too!
Kari: Please be careful
Tai: Goodbye Kari
Kari: Bye bye, Tai. Don't forget about me!