Phone Braver 2, also referred to as Second, appears in the story as one of the Phone Braver robots, a series of small devices that change between a mobile phone form and an active robot form. She stands out in the lineup as the female-type unit, with a design that gives her a distinctly feminine appearance. Like other Phone Bravers, she can switch between her mobile and active forms and can connect to machines, networks, and communication systems through the central artificial intelligence used by the investigating organization.

She was created as part of the same development program as the other Phone Braver units and was assigned as the partner of the agent Chigusa Mimasaka, who would later lead the special investigation team. Their partnership ended when Phone Braver 2 was destroyed by the renegade unit Phone Braver 01. Because this destruction takes place relatively early, her appearances are brief, and the story does not depict an elaborate individual personality, personal motivations, or a character arc for her. Her role in the narrative is therefore mainly tied to the background of Chigusa Mimasaka, who is introduced as her former buddy, and to the larger conflict with Phone Braver 01, whose actions removed her from the roster of active units.

In terms of abilities, Phone Braver 2 is a standard Phone Braver rather than a specialized model. Beyond her transformation ability and her access to communication and network functions, the story does not showcase any unique combat powers or distinguishing application for her. Her significance rests on being the female-type unit among the early Phone Bravers and on the abrupt end of her partnership with Chigusa, which forms part of the personal history surrounding the team.