Mukuchina Miyashita-san no shikiyoku channel is a Manga/Manhwa/Manhua in (English/Raw) language, SUGGESTIVE series, english chapters have been translated and you can read them here.
Kei Sakai, a high school boy, is in trouble. he is not very interested in anything and has no sexual desire. One day, he finds out about the existence of a mysterious beautiful girl, Yami, who becomes a hot topic on SNS from a part-timer work friend. Yami is an unknown idol in the internet world who gets overwhelming support from guys by uploading naughty videos and pictures that look too ridiculous. No one knows her front face… However, only Sakai remembers a woman who looks like Yami. That person was Saki Miyashita. A quiet high school girl sitting next to him in the same class, but Yami’s position, style is the same. Sakai has lost interest and sexual desire, but in order to find out the true identity of Yami, he decides to look for Miyashita. However, without knowing Miyashita’s trap, she will share a vile secret that is too dangerous…!!?