"She stands in-between every word spoken, every beat of our hearts, every breath of air we draw. She is the void between the stars that cradles them as they plummet through the great emptiness of space. She was here when the universe began, and she will be here when it ends – and forever keep it safe in the silence."
- - Hotaru Tomoe
Kima is the ultimate guardian of silence – the true keeper of the terror that follows in the wake of destruction and shattered dreams. Hers is the eternal burden of silence: every unseen glance, every unheard word, every unspoken thought that only silence will keep, because no-one else will.
Kima is nothing more or less than the manifestation of the consciousness whose sole purpose is to be aware of all that silence holds. She is as ageless as the silence she guards, for there is no movement in silence and hence no time.
Due to her forbidding task, from the dawn of the universe she took to an isolated existence. As the eons dragged on, she ended up wandering more or less aimlessly across the voids, not daring to involve herself on any personal level with the myriad individuals she'd encounter on her journeys, except those lost souls to whom silence was the only remaining outlet for their sorrows, fears, frustrations and hate. Continuously confronted by the darker sides of the sentient mind, Kima became increasingly aware of the impending danger that sooner or later she might become sufficiently provoked to unleash the ultimate judgement upon the universe and plunge it into the greater silence that lies beyond oblivion's veil. Thus she grew ever more solitary, desperate to shield all of creation from herself and to find a solution to her own mounting dread.
Eventually she stumbled upon the Solar system, finding herself inexplicably drawn towards its center. Knowing full well the general opinion regarding the nature of her element, she painstakingly made her way past the outer guardian planets, taking the outmost care to slip unnoticed into the inner parts of the system. And there she discovered it – the immortal kingdom of the Moon, the Silver Millennium, and most importantly its sovereign, the Queen of the Moon: Serenity. The unwavering, all-encompassing love for all living things that the Queen represented was to this traveller of voids like a dazzling aura of the purest light, and for the longest time Kima dared not draw near for fear of putting out that beautiful light with the horrible darkness that she had come to identify herself with.
To Kima's monumental surprise the Queen met her approach without the faintest trace of fright or revulsion, seemingly having expected the dark guardian's arrival for some time and even chiding her visitor for taking so long. Her mind and soul overwhelmed by the Queen's unfathomable mercy, Kima pledged her undying loyalty to the will of the Moon Queen and all the kingdom's inheritors besides, so that as long as there would be a Moon Kingdom there would always be someone strong enough to stop her should she ever become tempted to cross that final, terrible line. Thus Kima became the guardian of night and silence on Earth, moving with the ever-shifting evening dusk across land and sea so that troubled hearts could find a precious moment's respite from the haunting hours of twilight.
It is a great irony that this act of benevolence would spell the eventual doom of the magnificent Moon Kingdom. An ancient evil, hidden away in the heart of Father Sun, seized the opportunity and ambushed Kima, striking a near fatal blow and ripping from her the element of darkness. The evil power went on to employ its newfound vigour to turn the people of the Earth against their Prince and leader, Endymion, rousing all their contemptible, simmering angers and resentments and directing them towards the Moon – which of course had been the target all along: the power contained in the Phantom Silver Crystal, protected since time immemorial by the royal bloodline of the Silver Millennium.
The rest is legend. The Silver Millennium, besieged by the Dark Queen Beryl, fell to an unstoppable onslaught of destruction. Endymion was slain trying to protect the Princess of the Moon, and Queen Serenity herself sacrificed her life to ensure the future survival of the Moon Kingdom's legacy and to bring about a temporary recontainment of the evil power which would eventually be identified as the entity Metaria. Kima was reduced to wandering the deep, dark places of the Earth like a naked shadow, devoid of strength and purpose, only guided by the faint but desperate hope that somewhere, somehow the lost heir of the Moon Queen would reappear.
When Usagi Tsukino was first awakened to her destiny as a Senshi, Kima sensed the spark of the Silver Crystal lying dormant in Usagi's heart and swiftly made her way to Japan, where she quickly found herself caught up in the seesaw skirmishes between the Senshi Team and the resurgent Dark Kingdom. In the wake of the abduction of Mamoru Chiba, now identified as the reincarnated Endymion, Usagi finally confronted Kima who bereft of all other options chose to tell the terrible truth of her downfall at Metaria's hands and how Metaria and her subordinate, Queen Beryl, had proceeded to abuse the powers of darkness they had commandeered. Usagi's mercy won over the other Senshi's natural suspicion and Kima once again became an ally of the warriors of the Moon Kingdom, aiding them numerous times and earning their trust and respect. Still, even then the trauma of her ancient failure continued to haunt Kima's mind.
Not until Metaria's final elimination at the hands of the reincarnated Moon Princess would Kima be completely restored, as much by Sailor Moon's selfless act to defeat Metaria as the camaraderie and cheerfulness that Usagi would always pour onto her surroundings. To this day Kima remains implacably loyal to the Princess, who puts equal confidence into the reliability and capability of this most unlikely of allies.
Kima is not only the ultimate guardian of silence, but she also holds the power to unmake the entire universe at once – by simply choosing to no longer listen to it. Because of this she has had a strained relationship with the Outer Senshi, especially after the climactic final battle against the Death Busters where Kima's intrinsic connection with the Senshi of Silence, Sailor Saturn, was first revealed. At first the Outers regarded Kima with equal parts fear and wariness, as her very nature represents everything they had been striving so hard to contain – Haruka in particular holding a deep grudge towards her for a considerable period of time. Due to Kima's unquestionable dedication to the reincarnated Moon Princess and the repeated displays thereof, the Outers have since come to respect and appreciate the Dark Guardian's abilities and her relentless determination to follow the Princess to whatever end.
Following the events of Nehelenia's second invasion, Kima and the reborn Hotaru encountered each other seemingly by chance. Hotaru immediately showed an intuitive trust in Kima (much to Haruka's consternation) and the odd pair swiftly formed a fast friendship, which has helped mellow the standoffish Outers to the easygoing camaraderie of the Inners.
In her current form on Earth, Kima appears to be a couple of years older than Mamoru. She works as an exchange doctorate at the university where Setsuna is currently employed, and Haruka and Michiru continue their education after the destruction of the Infinity College. Kima socializes regularly with the Senshi, though she retains her withdrawn nature and taciturn demeanour, preferring to keep a background presence. She's generally quite formal but very patient and considerate, and can occasionally exhibit a quiet, shrewd sense of humour. She has become somewhat of a confidante to all of the girls, especially Usagi's troupe.
While Kima has grown fairly comfortable with her newfound friends, Usagi and Hotaru remain the closest to her – Usagi for her outgoing, amiable character and endless, unashamed kindness; Hotaru for the natural affinity in their shared element as guardians of silence. Hotaru in particular spends time with Kima on a regular basis, and it has been noted that Kima tends to become visibly more at ease when in the company of the enigmatic child. While they address each other with the etiquette expected of a young girl addressing a superior and vice versa, they both tend to express a rather conspicuous acquaintance with each other from time to time, up to and including a discreet, familial affection.
In battle, Kima can call upon the energies of shadow, darkness and silence to weaken or outright neutralize her opponents, literally stealing the enemy's abilities and turning them against themselves. She's not beyond engaging in physical combat and will often do so rather than unleash her terrifying powers. She can channel the very essence of silence into her own being to a greater or lesser extent, elevating her strength and speed to inhuman levels and enabling her to teleport from one shadow to the next at will, as long as the shadows are deep enough. Her strongest form is that of the Dark Guardian, where she becomes encased in armour woven directly from the silence over which she holds sway. This can only be achieved by Sailor Saturn directly summoning the power of Silence, for which she is the herald. While in this state, Kima and Saturn can communicate telepathically (which to some degree they already do) and even share each other's sensory perceptions.
It is possible for Kima to assume a self-induced version of the Dark Guardian, but in this state she is little more than a raging beast, nearly mindless with all the pent-up anger and pain that silence holds. Once gripped by the berserk fury of battle, only the Moon Princess herself can hope to stop this living entity of destruction from tearing reality itself apart.