Touhou characters in bikinis drawn by Nenobi, with a little extra "oomph" added to their chest size as a result of being "grown-up". For the series of posts specifically titled with "大人" preceding a character's name in the Pixiv commentary (Example: "大人咲夜さん" translating to "Adult Sakuya-san" or "Grown-up Sakuya-san").