Mahiro Oyama

Mahiro Oyama is a former otaku slacker and the brother-turned-sister of Mihari Oyama, having been transformed into a middle-school aged girl by one of Mihari's experiments.

Appearance
Mahiro's appearance as a guy has never been fully seen. It is shown that his greyish or pinkish-grey hair that was short cut with bangs that fully covered his eyes.

After being transformed into a middle-school aged girl by Mihari, Mahiro's hair now stretches to her lower back with a single strand on the top poking up. She is also now slightly smaller than Mihari and gives off the appearance of an extremely cute and adorable young girl. Due to Mihari having replaced all her male clothes, Mahiro is now seen wearing skirts and dresses almost exclusively, with a particular fondness for sundresses.

Personality
Mahiro used to be a degenerate slacker with a love only for manga with stories of bondage and sex slavery, and staying home playing video games. It was noted that before the start of the series, he hadn't left his house for two years. According to Mihari, Mahiro wasn't always like this. When they were younger they were very close and got along famously, but he stopped making time for her ashe got older and her achievements surpassed anything he could ever hope to achieve.

After being transformed into a girl by Mihari, Mahiro didn't put up much of a fight, though she did show some initial resistance to going outside, showing regularly, and putting up with all of Mihari's new rules for her. As time went on, her old personality started to fade away and she started exhibiting the personality of an adorable younger sister who loved dressing up and being taken care of by Mihari. The main aspect of her old personality that remained however was her love for video games, and she is seen playing them constantly in her spare time. Overall, the roles of Maharo and Mihari have since reversed with Mihari taking care of Mahiro rather than the other way around.

After being hit on the head by a box and temporarily losing her memory, and gaining the personality of a little girl in the process, some of this other personality has begun to leak through on occasion. This is shown by actions such as the occasional cutsey expression, and taking naps after eating cookies much to Mihari's frustration.