Maryberry battles severe shyness and social anxiety as a student at Flora Girls' Academy and member of the idol unit Sugar Pockets. She depends entirely on her specialized Berry Board communication device to translate thoughts into audible speech, being unable to speak directly to others, making it her primary means of interaction. Her character development focuses on overcoming these communication barriers. A transformative meeting with IV KLORE's Garnet sparks a change, leading Maryberry to gradually open up. She begins initiating social interactions more directly, like calling out to teammates for practice instead of solely using the Berry Board, marking her first observable shift in social engagement.

This growth is vividly demonstrated during Sugar Pockets' orchestral performances. Maryberry navigates visible nervousness on stage, showing increasing confidence during live shows and contributing effectively to the group's music. Her performance of "Wagamama Caramelize" in Episode 7, while imperfect, reveals her developing stage presence and ability to manage anxiety under pressure. This act directly inspires LiGHTs' Tiara to propose forming an orchestra unit, highlighting Maryberry's influence on other characters' motivations.

Extended franchise material, like the "Lapi! A competition full of witches! ~Our Concerto~" live stream audio drama, humorously places Maryberry on the "Useless Rejects" team alongside Rosetta, Alpha, and Lucifer, a lighthearted designation reflecting perceived shortcomings in magical or academic skills. By the anime's conclusion, Maryberry exhibits reduced dependence on the Berry Board while continuing performances and group activities with Sugar Pockets. Her journey illustrates a path from isolation toward increasing social integration within the academy.