At the time of birth, the right side of her body was paralysed, but the paralysis was cured within a few months.
[3] Morohoshi joined the Himawari Theatre Group at the age of three, inspired by her admiration for characters in Spirited Away.
In 2006, at the age of seven, she voiced Carrie in the anime series Red Garden and was shocked by the vocal performance of co-star Takehito Koyasu.
At the age of nine, she voiced Nina Tucker in Fullmetal Alchemist: Brotherhood, in which her "skillful" performance encouraged the staff to cast her as Betty in Heroman.
Since 2009, she has been active as a voice actor, in addition to performing in television dramas and on stage.