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Sakurai Minami (桜井 水波) is a student of First High School. She is a member of the Second Generation Sakura Series constructed by a laboratory linked to the Yotsuba Clan. She serves as Guardian of Shiba Miyuki.
Appearance and Personality
Minami's appearance is said to be practically identical to that of her aunt, Sakurai Honami.
Minami is dedicated and loyal in her duty as a Guardian for the Yotsuba. She is polite to all, but can't hide her emotions well when she wants to. She is appalled with the notion of being Shiba Tatsuya's "cousin" or calling her mistress, Shiba Miyuki, using terms too intimate for her status. Despite the warm affection and treatment the Shiba siblings give Minami by treating her not as a tool, but as a normal human being, she still tries to be resistant to this and sticks to her rigid professionalism.
She also respects her mistress and aspires to be like her as a magician, but is also aware about her extreme sensitivity when it comes to matters concerning her brother. She also respects Shiba Tatsuya and thinks that he is the more rational one among the siblings.
With a frank and logical mindset, she is critical and unmerciful in her thinking of others, as seen when asked on her opinion of Shippou Takuma by Tatsuya.
She is the daughter of the woman who shares the same genes as Sakurai Honami. With that, she belongs to the Sakura Series and will serve as a Guardian for the Yotsuba. Both of her parents were Augmented and are now deceased. After they died, she moved into the Yotsuba main house where she served as a maid. She was trained to be a Guardian and a servant/maid, different from Tatsuya who, except for some basic manners, was only trained to be a combat magician.
Minami is Shiba Miyuki's other Guardian, therefore she attends First High School as a First Year Course 1 student in order to fulfill her Guardian duties at all times. She was assigned to this post by Yotsuba Maya as an additional layer of protection against some possible moments in the future where havoc and destruction would occur. 
She is a member of the Cooking and Mountaineering Clubs at school. The official reason for this is so that she can improve her physical abilities. However, the truth is that joining the clubs is simply a means for Minami to waste time so that she can leave the school with Tatsuya and Miyuki. 
Born as second generation of magicians of modified genetic structure, she is said to has a more durable physical body than the previous generation. Thus, her magic abilities are also assumed to be better than the former generation.
As a member of Yotsuba Clan who will hold great duty of protecting the future Head of the Family, her physical abilities are fully maximized and heavily-trained as a combat magician by the main house of Yotsuba to the point that there is no more space for improvement.
As part of the Sakura Series, her specialty lies in defensive magic against powerful object and heat based attacks. Her potential is said to be on par with the Saegusa Twins, therefore possessing abilities on par with members of the Ten Master Clans. Since Minami is an indirect descendant of Sakurai Honami, it can be assumed (based on the universally accepted fact that later generations tend to be stronger then the previous ones) that Minami is just as skilled or perhaps even more then her predecessor, who was said to be highly gifted even among the Sakura Series. Her great skill and talent in magic can easily be acknowledged by the fact that she was entrusted with the protection of one of the prospective candidates to be the next head of the Yotsuba Clan as her Guardian. The Shiba siblings even speculated that Minami could have been the Freshman Representative, if she didn't hold back on the technical portion of the entrance exam. It should be noted though that the Shiba siblings probably weren't aware that Minami had to be brainwashed for three weeks to carve the necessary knowledge to pass the written portion of the exam.
Minami is highly skilled in using defensive magic, being able to deflect multiple rockets from a distance and countless bullets being fired at her at close range without any trouble. Though, its functionality and variability are not on par with the Juumonji Family’s "Phalanx", when judged solely on its utility as a defensive mechanism, Minami is able to match the Juumonji Family’s level even at the tender age of 15. Her magic power and heatproof barriers are first class in terms of invocation speed and scale of the Magic Sequence.
As a Guardian for the Yotsuba Clan, Minami is highly trained in body guarding VIPs and taking down enemies targeting her Yotsuba masters. As Minami has been raised as a combat magician by the main house of the Yotsuba, her physical abilities shouldn't be something that can be improved further. However, she isn't yet a perfectionist when performing her duty, as she does make mistakes time to time because of her young age and lack of experience in the real field.