Hanage is the pet slug who lives with the main character Milk. His name translates to nose hair, and he is depicted as a green, middle-aged slug with a mustache, a large pink nose, three tufts of hair, and purple spots on the sides of his head. He has a notable drinking problem and is characterized as an alcoholic. Despite being incapable of speech, Hanage is multilingual and can understand several languages. When his internal thoughts are expressed to the audience, it is through a narrative device referred to as the voice of Hanage's heart, where he delivers maudlin soliloquies that reveal an optimistic and daydreaming inner world, including hopes of one day meeting the woman of his dreams. Within the story, he accompanies Milk and the robot Tetsuko as a companion on the missions assigned by the President. His role is that of a passive sidekick, often present for the surreal adventures and absurd situations the group encounters, such as being kidnapped by aliens who ultimately reject him for being too unpalatable. His key relationships are with his housemates, the foul-mouthed and selfish Milk and the frequently abused robot Tetsuko, forming the core trio of the series' household. There is no substantial development for the character across the series, as he remains a consistent, mostly silent presence whose primary mode of expression is through the brief, poignant glimpses into his inner heart. His notable abilities include his inherent nature as a slug and his understanding of multiple languages, but he possesses no special powers or combat skills.