Romario is mostly seen drinking with Kusakabe. When Tsuna and the others came back from the Choice game, Hibari leaves because he hates crowds, and Kusakabe and Dino follow them. When Dino tripped from the stairs because his men weren't there, Romario came to Dino a few seconds later and is seen having liquor to drink with Kusakabe. Dino says to Romario to follow him.
Romario is almost always the subordinate that Dino has around to stop him from being so clumsy; this is most likely attributed to him being the right hand man.
Romario and Kusakabe seem to share a friendship. This is probably because Dino and Hibari constantly train with each other.
Romario and Dino trained so that now, Romario or one of Dino's subordinates can now be 1km away from him without him being clumsy. It is shown that this still needs training as Dino still falls down the stairs when Romario is just mere meters away.
He appears dining in a restaurant during Gokudera's past story flashback. The reason is unknown.
In the Future Arc, he is seen having white hair due to his age.