Asami Iwasawa is a member of the Afterlife Battlefront and serves as the leader, lead vocalist, and rhythm guitarist for the band Girls Dead Monster, which acts as a diversionary unit during the front’s operations. She is also responsible for writing the lyrics and composing the music for the band’s songs, channeling her thoughts and emotions entirely into her musical expression. Iwasawa has a calm and collected personality and is recognized by her peers as a cool beauty, though this reserved demeanor belies a deep and burning passion for her art. She is often so consumed by her musical ideas that she will wake sleeping band members in the middle of the night to share a new song. Beyond music, she has a notable fondness for udon noodles.

Before arriving in the afterlife, Iwasawa grew up in a deeply troubled and dysfunctional household where her parents fought constantly, leaving her without a room of her own and forcing her to live a gloomy, isolated life without friends. Her life changed when she discovered the music of a band called Sad Machine, whose lead singer came from a similarly broken home; his songs, screaming against the world's unfairness, saved her and inspired her to pursue music. Unable to afford an instrument, she rescued an abandoned acoustic guitar from a garbage heap, bought strings with money from part-time jobs, and taught herself to play, eventually busking on the streets. Despite having excellent grades, she chose not to go to university and moved to the city to focus on her musical career, working various jobs while tirelessly attending record company auditions. Just as she was on the verge of achieving her dream and making a major debut, she collapsed and was hospitalized due to a cerebral infarction. This condition was the result of an old head injury sustained when she was hit with a bottle while trying to stop one of her parents' fights. The stroke left her unable to speak, robbing her of her voice and her dream, and she eventually died in the hospital without ever recovering.

In the afterlife, Iwasawa finds herself able to speak and sing again, and she immediately dedicates herself to music. Her primary role in the story is to use Girls Dead Monster’s concerts as a diversion for the non-player character students while the other members of the Afterlife Battlefront carry out their operations against Angel. Her most significant moment occurs during a mission to infiltrate the girls' dormitory. After being interrupted, she breaks free and performs her song My Song on stage. In this performance, she finds the fulfillment she had been searching for in life, accepts her existence, and disappears, passing on from the afterlife. Her disappearance serves as the first major clue to the true nature of the world and the key to moving on.

She shares a key relationship with Hisako, another member of Girls Dead Monster, as the two formed the band after Iwasawa’s guitar playing inspired Hisako. Within the band, she interacts with other members like the mischievous Shiori Sekine and Miyuki Irie, with Sekine noting that Iwasawa is most comfortable speaking about music. Her character development is centered on finding peace through her art, realizing that her life was not meaningless because she was able to touch others with her song. Her notable abilities include her exceptional skill as a guitarist and vocalist, as well as her talent for songwriting and composition. She uses a Fender Stratocaster guitar with a Sienna Sunburst finish.