Guren (紅蓮, Guren) is a kunoichi who appears in the second Naruto Shippūden anime-exclusive arc. She is the female leader of Orochimaru's subordinates. She uses the unique Crystal Release brand of jutsu.
Personality Guren has shown to be very mysterious, apparently preferring to keep to herself despite having a strong loyalty to Orochimaru. During her introduction, she quickly showed herself to be a remorseless and sadistic person. When told by Kabuto that several prisoners would be fighting to the death, she became ecstatic to hear there would be a slaughter. Guren is also shown to be vain by the fact that when she used her Crystal Release: Jade Crystal Mirror, she looked at herself and said, "Lovely, as always." She has also shown to be very proud. When Naruto offered to carry her, she was embarrassed because she felt it was shameful.
She is devoted to Orochimaru to an almost obsessive state. This devotion was so powerful that she fell into despair when she learned she would not become Orochimaru's next vessel, isolating herself from the shame. It has also been shown she has a terrible relationship with Kabuto, as the two argue often, trading scathing remarks. Later, she meets Yūkimaru, and at first, she finds him peculiar and somewhat irritating. However, when Yūkimaru became ill, she cared for him, watching over him for an entire night, until she fell asleep from exhaustion. When she woke up, she found that she was alone - and went searching for Yūkimaru, who she found nearby outside under a camellia tree. She then develops a sort of friendship with him as she crystallizes a flower and tells him that the flower will never wither as long as she is alive.
Since coming in contact with Yūkimaru, Guren seems to be having conflicting emotions. While part of her still wants to be accepted by Orochimaru as his next vessel, another part of her seems unable to let go of the bond she has made with Yūkimaru to the point of protecting him even from Orochimaru's right-hand man, Kabuto. The emotions seemed to have become more confusing for her in her first one-on-one confrontation with Naruto, who stated bluntly how horrible and selfish a man Orochimaru really is.
After realizing the truth behind her past and how it connects her to Yūkimaru, Guren feels even more compelled to protect him, out of guilt and repentance for her past sins, as well as love - wishing to become an almost surrogate mother to the boy, to replace the mother she killed. She even goes so far as to turn her protection to Naruto, as they faced off against the small Three-Tails clones within the beast's stomach, telling him she would protect him to the death if he would watch after Yūkimaru. This is a great change from her previous interactions with Naruto, whereas she was stand-offish and combative, she becomes quite friendly with Naruto. Subsequently, Guren has also begun to have doubts over remaining loyal to Orochimaru, due to her grief over the horrible things she was made to do in his name, and the damage and pain he has caused Yūkimaru and herself.