Masami Iwasawa (岩沢雅美, Iwasawa Masami) is the leader of Girls Dead Monster and the band's lead guitarist and vocalist. She is voiced by Miyuki Sawashiro and Luci Christian whilst her singing voice is by Marina. She's also the heroine of Angel Beats! -1st beat-.
Iwasawa has chin-length pink-red hair with two locks of hair longer than the rest, extending to her back. Her eyes are red. She also wears the uniform of the SSS with her sleeves rolled up to her elbow. She wears flat calf high black boots instead of normal school shoes as well as black sweatbands on her wrists. As well as having a guitar with a tan or peach color that she finds in the trash.
Iwasawa has a calming demeanor, having been described by Yuri as the "cool beauty". While usually she is rather quiet, she is able to fascinate listeners by striving to create music that speaks her thoughts and feelings.
Iwasawa later reveals that she feels uncomfortable when interacting with other people as she experienced being gossiped behind her back when she was still living, and has once showed a facade to people to actually talk to her, hiding her true feelings inside. This eventually changed when she meets Yuri, who aside from Hisako has been the first person to show sincerity towards her.
In the manga, Iwasawa can be seen to have a rather comical attitude towards her band mate, Hisako, which often result in Hisako getting angry over Iwasawa. She is often seen as stubborn (as Angel whom she mentioned to be very persistant) at the beginning but as she got to know Hisako better, Iwasawa was actually a clueless, innocent bad-in-naming-the-band girl.
It is revealed that her parents often fought during her childhood. While staying away from home during one such fight, she listened to music from a band called Sad Machine that struck a chord within her. Inspired, she started to play saxophone then sing and after some time she began her music career. Unfortunately, just as she seemed to be getting into the business (and away from her dysfunctional family) she collapsed while working at her part time job as the result of a severe cerebral stroke that left her unable to move or speak. The cause of the stroke was head trauma she suffered as a child while trying to stop a fight between her parents, during which her father hit her with a beer bottle. She spent the rest of her life in a hospital bed paralyzed and silently cursing her fate.
Iwasawa is the leader of the band Girls Dead Monster, also known as GirlDeMo. As well as being the leader she is in charge of the vocals and lead guitar. She is also the one who writes the lyrics and composes the music for the band's songs. The songs are then used as performance pieces for concerts which turns out to be a diversion for the NPC students while the SSS proceeds with their plans to eliminate
In one occasion, she is forced to flee when she continues her guitar-playing antics, and there, she meets Hisako. Hisako asked Iwasawa to form a band with her which the latter refused. It was only after their first live performance then Iwasawa agreed to form a band with her.