Royal Knight AcademyEdit
Philuffy has been in love with Lux since childhood. Philuffy first met Lux seven years ago and played a lot together since Aingram House was the Old Empire's former associate. Due to their relationship as childhood friends, both Lux and Philuffy have a very close relationship and had nicknames for each other. Even as teenagers, Philuffy still calls Lux "Lux" and insists that he refer to her as "Phi".
When the two were reunited years later after Lux became officially enrolled in Royal Knights Academy, Philuffy was pleased to see Lux again but when Lux didn't address as her "Phi", Philuffy refused to response to him until he submitted and called her "Phi" much to her joy. Philuffy is shown extremely possessive and defensive when it comes to Lux such as when Lisesharte bluntly revealed that Lux saw her naked, Philuffy asked her back off and leave Lux alone. When her older sister, Relie set up a game where the girl who steals a red request paper from Lux within one hour will get him as her servant for a week, Philuffy ambushed Lux while he was hiding in the bushes and placed him in a submission hold from behind (pressing her breasts on him in the process).
Because of their close relationship, Philuffy has no qualms whatsoever when it comes to being modest around Lux such as sharing the same room, sleeping the same bed or even taking a bath together. Although, Philuffy's affections for Lux may cause him discomfort from time to time, Lux does indeed care for Philuffy and generally appreciates her friendship. In fact, Philuffy is the very reason why Lux participated the coup that led to Arcadia Empire's downfall.
Because Airi was Lux's younger sister, she got to know Philphie before the Old Empire's fall. Airi and Philuffy's relationship could be described as good.
Philuffy has a mutually good relationship with her elder sister Relie, despite their different personalities. Relie, however, got this mischievous side in her by bribing Philuffy with sweets in order to get her little sister to do something. In spite of this Relie cares about Philuffy and she would do anything for her sake, especially after she became the last victim (though later ironically "resurrected" by that very experiment)one of Arcadia Empire's vile experimentation.