Toyama Asuka

is a first-year high school student at Haneoka Girls' High School. She is Kasumi's younger sister, and classmates with Ako and Rokka.

Description
Asuka lives together with her parents and Kasumi. She is a year younger than Kasumi, though it's not always clear who is more responsible out of the two. She is much calmer than her sister, tends to be sarcastic at times, and is bad at showing her affection towards Kasumi. According to Kasumi, they used to fight all the time when they were in elementary school, but nowadays they get along well; Saaya even says that they're like good friends and she is a bit jealous about it.

In the 2nd season of the anime, Rokka invited her to form a band with her, but she declined. However, she promised to keep an eye for Rokka for possible band members.

In the 3rd season, Rokka finally met her and Asuka's role of watching over her ended. She then volunteered as a staff for the event "BanG Dream! Girls Band Challenge!", and watched Poppin'Party, Roselia, and RAISE A SUILEN perform together at the Budokan.

Etymology
Toyama (戸山): To (戸) means "door, entrance" and Yama (山) means "mountain". Toyama also refers to the Shinjuku ward.

Asuka (明日香): Asu (明日) means "tomorrow", and Ka (香) means "fragrance, aroma".

Trivia

 * In the 1st season, she was a third-year junior student at Hanasakigawa Girls' Junior High School and in the same swimming club with Yuri.
 * In My Design, My Texture, Kasumi reveals that she has started growing herbs together with Asuka.