Midori Hayashi

Nineteen years old, a fujoshi (yaoi otaku) and a doujinshi drawer, she is the older sister of Shoutaro. She is the one who forced Shoutaro into the cross-dressing in first place, to help her with the doujinshi sale in her expo stand. She also was the one who started Yayoi in the world of dounjishi. Source: NoHeart summary of chapter 1 and 2