Ken-nii-chan tells Goku stories about the lower world sometimes - about the people and the places and the food. Sometimes, when Goku is hiding in Ten-chan's room, Ken-nii-chan comes crashing through and shouts at Ten-chan for things he did in the lower world, so he tells Goku about monsters and Ten-chan without really meaning to. (He teaches Goku new words when he does that, only when he repeats them to Konzen to ask him what they mean, Konzen washes his mouth out with soap. It doesn't taste nice.)
Ten-chan tells Goku stories about anything he asks for, and he has books full of stories that he lets Goku read whenever he wants. Sometimes, when he tells Goku a story it seems like he's really telling Ken-nii-chan or Konzen the story instead, but when that happens Konzen looks angry and Ken-nii-chan looks thoughtful and Goku's figured out that those aren't good things.
(Sometimes when Ten-chan and Ken-nii-chan come back from the lower world Goku can work out his own stories from the smell of their clothes. They usually come back smelling of fire or salt - the sea, Ten-chan says when Goku asks him, water as far as the eye can see - and blood.)
Konzen doesn't tell Goku stories. He doesn't know any, he said, and Ken-nii-chan says that's because Konzen never does anything apart from signing forms and being a grumpy bastard, and Ten-chan smiles like he knows a secret.
So Goku grabs Konzen's arm and drags him away from his desk. He tells him everything he's learnt and everything he knows, trying to fill Konzen up with stories so that when he presses his face against Konzen, he can smell more than paper and closed up rooms.