Fab Four
From Kokorodatabase
The term Fab Four is used to describe the group consisting of Shimizu Arisa, Bob Pushkaboomda, Sarah Cohen, and Shirogane Ichigo. While this term is mostly used by the "real" Plum, the authoress who roleplays each of these characters, it could really describe the four, considering that outside of the café, they do spend a lot of time together. Although this is mostly due to the fact that Plum likes to drag the rest of them on random adventures at any given moment.
With Cannoli's addition to the group, it kind of invalidates the "four" in the title, although, in other ways, he could be considered as a subsitute insert for one of the other characters in certain moments, considering Bob (who often goes into hiding to get away from the cracked adventures) and Sarah (who's often working or visiting Roy) are usually missing in action. It's also been said that he could just replace Ichigo, considering she really belongs in a cateogory of her own anyway.