Murakoso has dark red spiky hair tied in two low ponytails. She wears a black blazer over her white shirt and wears a black straight skirt. She is also seen wearing a necklace. She always carries a sword as her weapon.
She seems to be a laidback person, and is always seen chewing bubble gum. However, when her superior was hospitalized, she is seen being frustrated and showed regret for not being able to guard him.
Murakoso is seen with Ango when Dazai meet up with him to negotiate something. 
Later after the Guild war, Murakoso is at the scene wherein a Special Division transport van was attacked. A little while, Ango arrives. Murakoso theng gives Ango the rundown of the scene wherein the transport van was attacked and the culprit is a lone attacked dressed as a postal carrier. Ango then asks what was missing inside the van to which Murakoso replies that it was Document No. I-75-81-A. Murakoso is intrigued about the document and asked what was it about. Ango responds that it was a report he made about Kyōka's ability, Demon Snow and her parents who were killed by it. Murakoso further asks Ango why look further into Kyōka's parents. Ango replies that the records of her parents were erased by the government which means that they are both on "their side".
After Taneda suffered from great injuries, which led him to being hospitalized. Murakoso, with Ango and Aoki, visit him at the hospital. Murakoso is seen frustrated by this event even asking Ango why Taneda is alone with the enemy. She and Aoki are left at the hospital guarding Taneda while Ango leaves to deal with the enemy.
- The character is based on the character in one of Ango Sakaguchi's novel, "Betrayal (裏 切 り)".