TV-Series
Description
The Shōbijin younger sister, whose personal name is revealed in episode 89 to be Imo, is one half of the twin fairy duo known collectively as the Shōbijin who reside on Monster Island alongside various juvenile kaiju. She and her older sister, Ane, are the closest companions of Chibi Mothra, acting as her self-proclaimed interpreters. The name Shōbijin translates from Japanese as little beauties, and the younger sister is often referred to in credits as Shōbijin younger sister or by her stage name, Cosmos, which the pair adopt in the second season when pursuing a singing career.

In terms of personality, this incarnation of the Shōbijin younger sister is notably different from previous versions of the characters, as she is portrayed as vain, bossy, and impertinent. Despite Chibi Mothra being perfectly capable of speaking for herself, her shy nature has allowed the much more assertive Shōbijin to take on the role of her psychic interpreters, though they do not seem particularly concerned with accurately conveying her thoughts. When speaking together with her sister, the younger sister often speaks in a monotone voice, but she speaks individually when angered or when alone with Chibi Mothra. The series reveals that the Shōbijin can disagree with one another and fall out of sync over petty arguments, such as what shallow qualities they look for in potential romantic interests. When they are in sync, it often seems to be when they are sharing a negative emotion, such as anger or unpleasantness toward others.

The primary motivation of the Shōbijin younger sister appears to be protecting Chibi Mothra, though her methods are often misguided. She and her sister take a confrontational and rude tone when meeting new monsters to shield Chibi Mothra from potential discomfort, but they can quickly change gears and attempt to set Chibi Mothra up on dates if she shows interest in someone, as seen when Chibi Mechagodzilla arrived on Monster Island. Their efforts more often than not only manage to embarrass or upset Chibi Mothra rather than help her.

In the story, the Shōbijin younger sister serves primarily as comic relief and as an interpreter figure, though her abilities are frequently called into question. When Chibi Godzilla enlisted the aid of the Shōbijin to translate the unintelligible roars of Chibi Anguirus, they merely claimed that Chibi Anguirus found them very attractive, a claim Chibi Anguirus immediately denied. Their attempts to translate the thoughts of others appear to be nothing more than either their own thoughts or outright guesses, leaving the true extent of their telepathic abilities a mystery.

The key relationship for the Shōbijin younger sister is with her twin, Ane. The two function as a pair, and their dynamic is central to their identity. When they fall out of sync and lose their ability to read each others thoughts, they become less effective and more argumentative. They are also close to Chibi Mothra, though their relationship is complicated by the Shōbijins tendency to speak over her and misinterpret her feelings. The Shōbijin have sometimes been portrayed as enemies to certain characters, including Chibi Mechagodzilla, Chibi Godzilla, and Chibi Hedorah, though these relationships fluctuate.

The Shōbijin younger sister shows development over the course of the series, particularly in her relationship with her sister. The episode Shobijin Slump reveals that they can lose synchronization over petty disagreements, but they can regain it when tapping into shared emotions like anger. Their pursuit of a singing career under the stage name Cosmos represents a notable development in the second season, as they attempt to channel their abilities into a more formal artistic pursuit.

Regarding abilities, the Shōbijin younger sister possesses telepathic capabilities that allow her to psychically communicate with her sister and with the other monsters of Monster Island, especially Chibi Mothra. However, as the series demonstrates, these abilities are not always reliable. The Shōbijin can fall out of sync with each other and lose their telepathic connection, though they seem able to regain synchronization when giving into strong emotions together.