Roll

Roll (ロール Rōru) is a kind-hearted humanoid robot created by Dr. Light to be a housekeeper, helping around Dr. Light's Laboratory by cleaning and cooking. She is the "little sister" of Mega Man and Proto Man. Her dream is to one day open a hospital and help people.[1][2]

Roll is one of the few female characters in the original Mega Manseries, and the only female humanoid robot until Plum and Splash Woman were introduced into the series. In spite of her minor roles in the games, Roll is perhaps one of the most special and well-known characters in the entire Mega Man series, and remains a fan-favorite to many. She is especially well known as the first female character ever in the Mega Man universe. She is also special in a sense that she, with her counterparts Roll.EXEand Roll Caskett and appearances in other media, combined, has made the most appearances of any supporting character in the Mega Man series as a whole.

Mega Man (Ruby Spears)
Roll is one of the main characters in Ruby-Spears's Mega Man animated series, appearing in all episodes. She was created as a teenager in the cartoon, and her arm can transform into several home appliances, which she can use for combat. According to the first episode, she apparently adapted these attachments as weaponry herself, whilst Doctor Light was modifying Rock into Mega Man. Although usually below par in combat compared to Wily's robots, she would often fight alongside Mega Man, often defeating Robot Masters on her own. She is voiced by Robyn Ross, except for a single episode, in which she is voiced by Kathleen Barr (note that there is much debate over how many episodes Ross voiced Roll in, with some sources saying Ross and Barr alternated the role in the first season before Ross became Roll's full-time voice in the second season).

Mega Man: Upon a Star
In the OVA Mega Man: Upon a Star, Roll tries to stop Dr. Wily from stealing Dr. Light's time machine in episode 2, and is taken hostage. She is later rescued by Mega Man. In episode 3, Roll tries to help Mega Man in the battle against Dr. Wily.