Ryoku, a turquoise and light-blue Chinese dragon, is bound to Natsuki Sasahara as her Ma-Pet companion. Sent from Fairyland alongside two other magical creatures, he seeks human girls destined to become princesses linked to Kaguya-hime’s legacy. His diminutive stature and dragon-like form often lead others to mistake him for a plush toy, sparking recurring confusion.

With a playfully mischievous streak, Ryoku teases Natsuki about her guarded emotions, balancing his role as both guide and provocateur to spur her personal growth. Despite his mythical origins, he gravitates toward cozy domesticity, nestling into a plush pillow cushion and miniature blanket during rest.

A memorable incident reveals his vulnerability to mundane chaos: after devouring a fiery curry dish made by Atsui-sensei’s wife, he temporarily gains fire-breathing abilities, startling observers who assume supernatural forces at play. His mission occasionally falters through absurd mishaps, such as amnesia episodes that leave him and fellow Ma-Pets bewildered about their purpose—and even the identity of Lilpri.

Ryoku’s core duty involves guiding Natsuki’s transformation into Kaguya-hime and harvesting “Happiness Tones” via musical performances. These efforts anchor the overarching quest to mend Fairyland by uniting human emotional resonance with magical realms. His presence weaves mischief and mentorship into Natsuki’s journey, reflecting the delicate interplay between duty and lighthearted companionship.