Unbeknownst to Rune, Somnus is his biological uncle.

Eden essentially adopted and raised the young Rune when she'd found him as a bappy, alone and vulernable. As a craftperson and jeweler, Eden found that Rune took quite a liking to the soothing melody of her chimes and music boxes, which only further motivated the symprite to create more for her little brother. Rune finds the ultimate comfort in being with Eden and often looks to her for guidance and advice.

Unbeknownst to Rune, Somnia is his biological mother.

Luna is Rune's overprotective watch-Byun basically LMFAOO He adores her, but is respectful of her boundaries - which, in return, has her trusting Rune more than anyone else.

Etoile is Rune's adoptive older sister - biologically Eden's sister. He's always found comfort in Etoile's soft, cloud-like fur and warm hugs (even if they are, at times, smothering). He adores listening to her talk about the stars and about her travels across Capricorn-13.

Rune became fond of Ceres the moment he laid eyes upon them. Met by chance in a local marketplace, Rune was instantly captivated by their air of elegance and regality. He initially felt conflicted between introducing himself to the siren-like beauty, or shying away to prevent making himself a fool in front of them - but his curiosity for this bewitching stranger eventually won him over. They'd quickly come to bond, often over tea, through their shared passions and interests, though it'd take Rune some time to get over his initial lovestruck awkwardness around Ceres. Despite becoming more comfortable around Ceres, Rune's affections for them would only continue to grow...

Rune and Sadako happened to come across one another during one of Rune's routine trips to the Swamp territory for its local herbs and greenery. Sadako had initially startled Rune (unintentionally, of course), but was rather pleased to hear that she was quite knowledgable in herbology and the local foliage as well. The two fell into comfortable conversation while searching for Rune's specific ingredients, discussing their shared interest in, not only herbology, but the occult and astronomy as well. The two are essentially witch-buddies now lmfao