It’s DLNs 001 and 002; they’re housekeeping robots that respond to the callnames “Rock” and “Roll.”Rock is modeled to look like a young boy, and can take a combat form. In this form, he also responds to the callname “Megaman.” Roll is modeled to look like a young girl, and despite not having a dedicated combat mode, is capable of basic combat to protect her creator.
Hardman gets to interact with Rock the most. Despite his former programming saying to destroy Rock, Hardman actually quite likes Rock, and wants to be friends with him. He hopes Rock knows that any attempts to punch or flatten him weren’t personal.
Hardman is less familiar with Roll, but she seems kind. He’s a little nervous of her because he has fought Rock in the past, and he hopes she doesn’t think he’s a bad robot because of that.
They’re both technically Hardman’s half-siblings.