Behind her skills in knowing how to defend herself, fighting, using all kinds of weapons and kill the target in her missions, she learned fighting until 11, she started to learn japanese weapons with the help of her brother Scarf, the SHSL Ninja. Her brother wanted her not to be hurt by someone else even if they are bad at fighting, he wants her to survive when he isn't on her side. One day, when they're training by using the weapons on the mannequins, they heard the doorbell which they don't know who. She decided to go check who's outside of their house, she saw that no one was there outside until she saw the envelope which she doesn't know what is about.

She took the envelope, she went to her parents and gave it to them. When her parents are reading, they are shocked that they need one of their child to become the assassin even if there is the least members or remaining assassins in the building which they'll have to sign up. If they can't do it, then the threats are coming after them, since they don't want that to happen, they decided to go to the alleyways to sign up for Cowboy Scarf to join.

They got the schedule for them to put her to the building where they will go. She went to the building for her to train there for about 2 years and after two years, she works there for the missions which she have to assassinate the victim. She thought that she might murder a random people at first which she got traumatized, her parents and her brothers comforted her since it's her first time doing the missions.

That's until she felt relieved during the discussion which she have to take out one of the crews of the other assassin groups one by one since she doesn't have to kill the random people but the other crews for killing the former crews of the assassins in other groups. Because of that, two groups are against each other since they've joined the different groups of assassins which she have to take down any of the crews which she is told by her boss.

While she was there in the building for missions which is told by her boss, she made friends with the other assassins when they first met and get along with each other even if the others are jealous that she kill the entire crew more than them which she earned the title of the SHSL Assassin.