Temptation of Shiro Gal & Kuro Gal is a Manga/Manhwa/Manhua in english language, Comedy series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Rei, the white gal, and Naro, the black gal, gets their classmate "Otaku-kun" involved in one thing or another. You'd think the two of them were seductively tempting Otaku-kun, but the one who was interested in Rei was the black gal next to her, Naro... The Yuri web manga that gained popularity, has announced that it's been serialized in a tankoubon volume with over 20 pages drawn.