Boys Gilding the Lily Shall Die!? manga volume 3 features story and art by Yomogimochi.

As resentment toward Aikawa's unreliability grows, the members of Nanryo High's ensemble club move forward with their plan to remove her from the first trumpet position. However, Aikawa unexpectedly finds an ally in Inukai, one of the band's percussionists. Recognizing the rising tension among the club members, Katagiri devises a plan to foster teamwork and unity.

Complicating matters, Mika Inui, Inukai's childhood friend and a senior percussionist, is determined to oust Aikawa at all costs, fearing her presence could jeopardize their dreams of winning the prefectural competition and beyond. As the ensemble tries to trust one another and work together, Aikawa and Katagiri begin to open up, realizing their initial motivations for being near each other have slowly transformed into something deeper.