Hazuki Morikawa is a central character in the anime Just Because!. She is a third-year high school student whose family has tended a farm for generations, a responsibility that has instilled in her a grounded and mature perspective on life. She is a member of the school's concert band, where her instrument of choice is the trumpet, a detail that initially draws the attention of a classmate.

In terms of appearance, Hazuki has a delicate and sweet look. Her long black hair is typically tied up in a ponytail, and she has slightly drooping violet eyes with a distinct mole located under her right eye. Her uniform is always worn neatly, reflecting her orderly nature. Her personality is notably calm, reserved, and unassuming; she is not the type of student who stands out or seeks attention from others. Reflecting her responsible family role, she is often seen performing various household chores and caring for her younger siblings. She has three younger siblings, including a set of twins, and her familial duties often take precedence in her life.

At the outset of the story, Hazuki appears largely uninterested in romantic relationships, having already set her sights firmly on her academic future and having decided on the college she wishes to attend. This focus on her path forward is a primary motivation for her character. Her personal journey involves navigating the unexpected romantic interest from her classmate Haruto Soma, a baseball player who was inspired to pursue her after seeing her perform with the band. Their relationship forms a significant secondary narrative within the anime, one noted for its mature and realistic portrayal of an adolescent romance.

The development of Hazuki's character centers on her gradual openness to this relationship, which challenges her initial disinterest in romance. She must balance her burgeoning feelings with her existing commitments to her family and her educational goals. Key to her story is her interaction with Haruto, whose determination and shyness clash and ultimately intertwine with her own quiet strength. While she may not be as outwardly expressive as some other characters, her decisions carry significant weight and lead to a resolution that many viewers found rewarding. Hazuki's notable abilities lie not in grand gestures but in her quiet competence: she is a skilled trumpet player, a responsible and caring older sister, and a person capable of deep, steady affection once her heart is engaged.