Mayuri Shiina is the childhood friend of Rintarou and his “hostage”. She is lab member 002. Mayuri works part-time waiting tables in cosplay in a maid café. She usually makes her own cosplay outfits in Rintarou’s “lab”. She uses her paycheck from the maid café to bring food and snacks.
Mayuri can be very naïve and childish. She gives people and even herself adorable nicknames without their permission like Okarin (Rintarou) and Mayushii (herself). She has a hard time following the terminology the rest of the lab members use but her simple train of thought can be very useful. She doesn’t get offended by Daru’s perverted mindset making her the perfect companion for Rintarou and Daru.
She cares a lot for Rintarou’s health and well-being doing what she can to provide him with his usual Dr. Pepper. She tends to put significance in detail that people tend to breeze over which proves to be useful in several occasions.
She gets upset when people argue around her and isn’t very good at taking hints but sticks around because of her optimistic outlook and simply because it’s fun for her.
Mayuri is a short girl with black hair reaching her neck and grey pupils. Her hair is ruffled at the back and the side. She usually has a gentle smile or a confused look on her face.
Mayuri wears very simple but comfortable clothes. She wears one-piece, light-blue, summer dress with a hat with the same color accented with a white stripe. Under her dress are leggings.
She also wears a black and white maid outfit with a blonde wig with a ponytail at the May Queen Nyan-nyan.