He quickly becomes friends with the player, along with Rhythmi, during their time in the Ranger. After graduation, he was assigned to Fiore, unlike the player. There, he met his partner, Buizel. He appears multiple times in The Almia Times where some of his rescues in Fiore are shown. He aspires to become a Top Ranger, which is eventually accomplished, and by no mere coincidence, at the same time as the player. He is declared the twelfth of twelve rangers to become Top Rangers. Later, on a mission to get the Yellow, he is kidnapped by Health in Hippowdon Temple and held for ransom, his Styler stolen so Heath could lure the player to him. The player has to hand in the just obtained yellow gem to Heath to rescue Keith, and after he obtained the Yellow Gem, Heath flees to the Altru to secure the gem so the shadow crystal could not be neutralized. He later assists the player during Operation Brighton, saving the player from Darkrai's Dark Power Field Move.
After the game, he is rarely seen. He cannot be found regularly, and will only appear when the player completes the Browser, conquers the Capture Arena, and finishes a certain quest.
On Ranger Net, Keith will partner up with the player for the mission "Liberate the Tower!