When they first met (not counting the Have Time, Will Travel arc, Harribel was polite and courteous to Ben, and remarked that he had good manners when he managed to keep himself from staring at her. When Ben chose to be one of her Fraccion, Harribel was surprised, but nonetheless did not protest.
Ben slowly began to gain Harribel's trust by saving her Fraccion from Nnoitra Jiruga; this was particularly important in Harribel's case, since she was one of the few Espada who cared about their Fraccion. When Ben used Way Big to give Nnoitra a brutal beating in retaliation for attacking Apacci, Harribel was touched.
As time passed, Harribel's feelings towards Ben blossomed into love, going as far as to betray Aizen in order to help Ben. Her love for Ben greatly increased after she recovered her memories at the end of the Have Time, Will Travel arc, and soon after, they began a relationship, sharing their first kiss.
Nelliel Tu OdelschwanckEdit
Initially, Harribel saw Nelliel as a rival for Ben Tennyson's affection, and the feeling was mutual. This rivalry did not, however, stop them from working together (and doing so quite effectively) when they needed to. After Ben agreed to "share", their rivalry was toned down somewhat, though both are hoping to one-up the other in the competition for being Ben's "favorite".
Unlike most of the Espada, Harribel deeply cares about her Fraccion, being something of a mother figure to them. When they were Hollows, she took them in and became determined to ensure their safety. As such, she will brutally attack anyone who threatens them, even beings more powerful than herself. Her Fraccion, in turn, are fiercely loyal to her, though at one point they did consider her a rival for Ben's affections.
Harribel respects Starrk, likely because he, like her, is not arrogant, brutal, crude, or overly violent. When she betrayed Aizen for Ben Tennyson, she expressed hope that Starrk could be convinced to defect as well and comforted him after he killed Baraggan by saying that Ben was a true friend, something Aizen never would be.
Harribel and Ulquiorra share a mutual respect; according to Ulquiorra, Harribel is the only Espada he respects. This did not stop her from attacking him on Ben's behalf. Ulquiorra would frequently mock Harribel's love for Ben Tennyson and express confusion as to why she did not simply take him by force. Since Ulquiorra's defection, it is unknown what they think of one another, though she did seek his aid in learning how to achieve the Segunda Etapa.
Harribel was initially quite loyal and respectful to Aizen, holding his power in high regard. However, after meeting Ben Tennyson, she gradually became disillusioned with Aizen. Aizen, in turn, was outwardly polite towards her, but in reality viewed her as a pawn to further his own ambitions, like his other subordinates. Midway through Volume I, she became enraged when Aizen threatened Ben's safety, going as far as to betray him on Ben's behalf.
Harribel's antipathy towards Aizen evolved into outright hatred by the end of the Have Time, Will Travel arc; upon realizing that Ben had saved her from the Hammerhead Arrancar and that Aizen had hypnotized her and her Fraccion, she silently declared that Aizen should consider himself fortunate that he is already dead, otherwise she would have made him suffer for his actions. She goes as far as to refuse to refer to him by name.
Harribel and Baraggan hated each other from the day they met. During his reign as the "God-King" of Hueco Mundo, Baraggan would often try to bully Harribel into serving him, but was met with refusal each time. This animosity did not deteriorate when they became Arrancar. A prime example of Harribel's contempt for Baraggan was when the latter attacked Ben Tennyson; despite being of inferior rank amongst the Espada, Harribel drew her Zanpakuto, stabbed Baraggan in the side, and menacingly threatened him.
Nnoitra, being a misogynist, frequently insulted and challenged Harribel like he did with Nelliel Tu Odelschwanck (Harribel's predecessor). Harribel, in turn, simply ignored him for the most part, but whenever he went too far or attacked her Fraccion, she would quickly overpower and threaten him, much to his fury. When Nnoitra suggested killing Ben Tennyson at an Espada meeting, Harribel - having grown fond of Ben - gave him a scathing look and secretly wished that Ben had used Way Big to break Nnoitra's jaw.
Grimmjow, being quick to pick fights with others, likely tried to provoke Harribel almost as often as Nnoitra did, though as with Nnoitra, Harribel simply brushed him off as unimportant.
Genryusai Shigekuni YamamotoEdit
Harribel's maternal affection for her Fraccion is retained in this timeline as well, with her being willing to do anything to protect them and them feeling the same way towards her. This included mounting an attempt to rescue her after she was captured by the Vandenreich, an operation that succeeded with the help of Ben Tennyson and several powerful Arrancar.
Initially, Harribel was intrigued by Ben, and seemed to respect him for what he was. However, the more she saw of him, the more he piqued her curiosity. They seem to be getting closer as time passes, though.
Nelliel Tu OdelschwanckEdit
Haribel and Nelliel respect one another.
Harribel was initially quite loyal to Aizen. However, she viciously attacked him after he betrayed her.