Bishoujo ni Natta kedo, Netoge Haijin Yattemasu.

The story follows the high school student Jintarou Futsu, whose confession was rejected by his crush. His misfortune continues, as news of a gender-change disease turns Jintarou into a beautiful silver-haired girl. The shock of it causes him to try to escape from reality by playing the VRMMO, Clan/Clan... His game character uses the same girl appearance as in real life, and the Alchemy skill, which most players call a trash skill. He meets lots of fellow adventurers, and becomes stronger within the game world of Clan/Clan's slogan, "When one becomes an adventurer, they can fight, steal, control, explore, invent, create, and do anything as they like." He meets a wide variety of adventurers that help him grow while hiding what happened to his appearance as a bug to his friends who also play the game, and hides the fact that he had become a girl in real life. When summer break is over, he will have to show his face at school. This is about one of the best National-class adventurers, the story of the Alchemist who won a war without even taking a single step. When a normal high school student suddenly turns into a beautiful girl, what would they do? The answer is to that is to become a net-game addict! (Source: Shousetsuka ni Narou, translated)