Mary O.

Mary O., known as Mashiko (ましこ, Mashiko) in Japanese and British English texts, is the manual's guide in Super Mario Maker. She can be spoken to at any time by tapping the green manual icon on the game menu. The game's manual was also accesible online on the official website before the site was repurposed for Super Mario Maker 2. Her role is to assist the player and share information about the game's content. Her appearance is that of a young female with blue eyes and dark hair, and a headset on. She also wears a pink shirt, and a black vest with Mario's emblem. Mary O.'s name is a deliberate pun on an common mispronunciation of Mario's name. Her Japanese name, Mashiko, is a play on "Mario".

A March 2016 update allows players to play as Mary O. in a construction outfit through the Costume Mario power-up. To unlock the costume, players have to clear the special Event Course created after her, titled "Mary O.'s Lunch Break". There are also special Event Courses created by her ranging back to October 2015, though those do not involve her costume.

A series of online comics starring her and Yamamura, titled Super Mario Maker: Crash Course, were released on the official Super Mario Maker website. The comics reveal some bits of her personality, most notably the fact that she is an incessant Yoshi fangirl.

While Mary O. does not return in Super Mario Maker 2, her role is fulfilled by another apprentice of Yamamura's named Nina.

Super Mario Maker online comics

 * This go-gettin' gal is fun and friendly. She also knows EVERYTHING about how to play Super Mario Maker! But when it comes to actually creating fun courses, well... (Episode 1~3)
 * This go-gettin' gal is fun and friendly. She also knows EVERYTHING about how to play Super Mario Maker! But when it comes to actually creating fun courses, well...thanks to Yamamura's helpful tips, she's getting pretty good! (Episode 4~7)
 * This go-gettin' gal is fun and friendly. She also knows EVERYTHING about how to play Super Mario Maker! And when it comes to actually creating fun courses, well...thanks to Yamamura's helpful tips, she's a pro! (Bonus Episode 1)

Super Mario Maker for Nintendo 3DS

 * Digital manual description: Fondly referred to by her peers as "everyone's older sister," Mary has a lot to teach you about Super Mario Maker for Nintendo 3DS. She knows just about everything there is to know about the game, but when it comes to actually making courses... Well, she hasn't had a lot of hands-on experience!

Trivia

 * If the player taps on Mary O.'s face on the Wii U GamePad's User Info page, she will appear shocked.
 * According to Nintendo of Japan, Mary O.'s Mystery Mushroom costume's voice is shared with Yu Ayasaki from Daigasso! Band Bros. P, who also appears as a costume.