Tsubame Kochou forms one-third of the demonic Butterfly Triplets, leading a faction opposed to the Lotus Association alongside her sisters. Their followers don black veils and possess the signature ability to morph into butterflies, a power integral to their mystique. While all three sisters exude mischief, Tsubame distinguishes herself as the most approachable, frequently positioned to the left in their seated arrangements.

The trio orchestrates theatrically chaotic schemes, exemplified by the "Beautiful Girl Imprisonment Incident." Tsubame sparks the event by declaring Yūrika irresistibly cute, masterminding her abduction. She subjects Yūrika to playful domination—enveloping her in cosplay attire, first stripping away her clothes, then swathing her in a plush bunny costume. Tsubame escalates the antics with tickling sessions and binding her captive in pink ribbons, all while the sisters proclaim themselves Yūrika’s "onee-samas" and designate her their collective "doll."

Outside their rivalry, the trio clandestinely crafts yaoi dōjinshi centering on protagonist Tōka Kamiazuma. Though Tsubame’s specific role in this endeavor remains undefined, her presence amplifies the group’s trademark theatrics—their laughter echoing in stylized "ohoho" cadences from behind ornate fans, cementing their reputation as flamboyant agents of supernatural mischief.