Spin-off of Steins;Gate, based on the Kurisu route of the Hiyoku Renri no Darling game.

Welcome to the School-Approved Lingerie Club. For friends struggling with ill-fitting underwear as their bodies change faster than their knowledge can keep up. Centered around Himeko Katsuragi, the Lingerie Doukoukai is formed to deepen understanding of undergarments! Discovering the right way to wear them, mastering different styles, and finding a new version of yourself...!! A passionate work depicting the affection and hopes of young girls, by rising star Chisato Hatada. (Source: Kadokawa, translated)

One-shot published in Harta volume 16.