Uno and Rock initially did not get along when they first met as Uno was annoyed by Rock's stupidity and impulsiveness and Rock was annoyed by Uno's arrogant and bossy attitude. Despite this, the two seem to get along in the present time, though they have the least amount of interaction among the four. However, the two do share some things in common, such as being the tallest and oldest of the group along with a similar interest in women (though Uno is far more interested and perverted than Rock). In addition, despite being annoyed by Rock's stupidity and love of food, Uno himself shows he does also have an appreciation for good food, at one point sharing Rock's sentiments about wanting to eat a stone oven cooked pizza.
He enjoys teasing Hajime and challenging him to fights, which he always loses. Hajime gets annoyed by his antics but takes advantage of Rock's simple mindedness to keep him in line, usually baiting him with the lunch menu to keep him calm.
He is shown to have a good relationship with the assistant chef, often complimenting his food and getting extra food such as cake in return. The two are very friendly with each other and Rock is not intimidated by Shiro's appearance, something Shiro is grateful for. However, he was annoyed when Rock took his pet cat and quickly took him back.