That Boy is Joe Kido

'''The children now know that the Holy Digimon is the key to saving Tokyo from the blackouts. They attempt to cross the sea to get to the continent, but they're suddenly attacked by a mysterious whirlpool.'''

Summary
The reach the sea, but scouting by air reveals a whirlpool that begins attacking them. is shot down, stranding them in the water as easy prey for Gesomon. rescues them and takes them back to safety, explaining that Gesomon attacks anyone who tries to cross the strait. He also explains that he too is a partner to a DigiDestined:. Unfortunately, Joe is too focused on his studies, believing that the search for the Holy Digimon should be left to the adults. In doing so, he rejects both his status as a DigiDestined and Gomamon's partnership. The other DigiDestined decide to continue their journey and form a plan to deal with Gesomon by drawing it from the sea to land. Gomamon volunteers to be bait, and when the subject of Joe is brought up, he explains that he understands the worry and confusion that Joe is undergoing, and expresses belief in his partner. Joe, not as unaffected as he appears, watches and listens out of sight.

They enact their plan, but Gomamon is heavily injured during the chase. Joe runs out to aid Gomamon and carries him away from danger. and digivolve to deal with the threat, but lose the upper hand when Gesomon manages to escape to the water. Gomamon and Joe have a heart-to-heart, bonding over the kindnesses they shared together when Joe first arrived. Joe finally accept their partnership, unlocking Gomamon's ability to digivolve to. As a fellow marine Digimon, Ikkakumon is able to fight evenly with Gesomon in the water, eventually winning with the aid of the other Digimon. The DigiDestined are then able to continue their journey to the Cloud Continent, with Joe and Gomamon joining them.

Digivolutions
(Number indicates order of occurrence.)