Seven / Wu Liuqi (伍六七, Wǔliùqī) Voiced by: He Xiaofeng (Mandarin, Cantonese); Saito Shinji (Japanese); Ronny Chieng (English) The protagonist of the series, also known commonly as Seven. A hairdresser whose real identity is a fearsome nameless assassin, but loses his memory due to unknown reasons. His current name is given by Ji Dabao, who is also his saviour when he loses his memory. He is ranked 17369th in the assassin list, though his real ability means he is far more powerful than the current rank he obtains. His real identity before the memory loss is one of the seven powerful shadow assassins of the Xuanwu Kingdom, with his codename Qi (柒). Despite memory loss, he is able to manipulate his scissors, which allows him to make the scissors as lethal as his real deadly sword. When he is in coma, his memory is temporarily restored, with his power doubled than the original, with his voice also changes from Mandarin to Cantonese. He has an oddly romantic relationship with Plum Blossom Thirteen. After the end of the 2nd season, he decides to return to Xuanwu Kingdom to find out what happened to his past. He always wears his White hoodie, in which is written the initial for Seven (motive to his name).

Thirteen / Plum Blossom Thirteen (梅花十三, Méihuā shísān) Voiced by: Duan Yixuan (Mandarin); Naoko Matsui (Japanese); Jennie Kwan (English) The unnamed youngest daughter of Plum Blossom Master. She has a strained relationship with her father, as her mother divorces from him due to his obsession with having a son, her dad having only thirteen daughters prior to bringing a new wife and his first son. She loses her mother due to a murder, before a hired assassin (who is later revealed as Qing Feng) comes to avenge her mother, causing Thirteen to seek Qing Feng for training and has vowed to defeat all men, be it her father or else. She is tasked in murdering Seven and bringing in the legendary sword, but her attempts tend to be disrupted with comical reasons, including a moment of kissing. However, Seven is the only person who does not care about her past and treats her like a normal girl, which emotionally changes her heart, and she harbours her feelings toward Seven since. Toward the end of the second season, she is one of the people to realise Seven's true identity.

Ji Dabao (鸡大保, Jī dà bǎo) Voiced by: Jiang Guangtao，Yu Haowei (Mandarin); Kōji Ochiai (Japanese); Jas Patrick (English) The manager of Wu Liuqi's barber shop, and also the person who saved Wu Liuqi's life two years ago. Although having a chicken-like appearance, he is in fact, a very powerful person, capable of transforming into anything if this is useful for his assassination task, usually given to Wu Liuqi instead. He has previously killed King Pheasant, who murders his friend, before freeing himself from the farm life and becomes an independent person.

Ji Xiaofei (鸡小飞, Jī xiǎo fēi) Voiced by: Zhao Han (Mandarin); Nakano Saima (Japanese); Jill Bartlett (English) Dabao's adopted son. A mixed hybrid between his late father and an unnamed pigeon, he is often around with his adoptive father.

A prequel manhua series, Scissor Seven: Black and White Twin Dragons, has been published on Tencent Dongman since 2021 across two volumes, written by Hei Bai Shuang Long and published by AHA Entertainment, and focusing on the adventures of two best friends, Bai Qi and Mo Lang.
A film sequel to the series' fourth season was announced at the end of the fourth season's final episode.