Hikaru Amakusa is a main character in Love Live! School Idol Musical the Drama. She is a second-year student at Tsubaki Takizakura Girls' High School and a member of the school's idol club. Her image color is Evergreen. Physically, Hikaru has long dark blue hair that she typically ties into a high ponytail, paired with dark purple eyes and a slight cat-like mouth. She is often seen wearing a watch.

Personality-wise, Hikaru is characterized as being straightforward and bold. She possesses a very athletic and optimistic nature, able to view situations objectively. Within her group of friends, she frequently takes on the role of the straight man, particularly when reacting to her classmates. She is known for being direct, which led her to be the first person to suggest that her friends try becoming school idols.

Before joining the idol club, Hikaru was already a member of the school's basketball club, and she continues to balance activities in both clubs. Her athletic background and high stamina serve her well in her idol training. Her notable abilities extend to all types of ball games. In the television drama, she is seen wearing apparel featuring the Los Angeles Lakers, indicating an interest in basketball at a professional level.

Hikaru is classmates with Rurika Tsubaki and Maya Mikasa. She maintains a busy schedule, often rushing between meetings and training sessions. Her straightforwardness helps her cut through indecision, but she does not enjoy dealing with small details or bugs. Her favorite food is sushi, while her least favorite is the pickled plum umeboshi. Her best subject is physical education.