“Otokonoko” refers to a 2D cross-dressing boy who is as cute as a girl. Essentially, he is a creature that cannot exist in the 3D world. This book tells the story of a man in his late twenties—who still avidly reads Shonen Jump—as he recklessly strives every day to cross that dimensional barrier. Nanami Igarashi is the son of Yumiko Igarashi, the manga artist behind Candy Candy. Having inherited his mother’s genes and become a full-fledged otaku, he used to secretly borrow his live-in girlfriend’s (a cosplayer) clothes and makeup while she was out to enjoy cross-dressing on his own—but eventually, she discovered his hobby…!!
(Source: Jitsugyou Nihon-sha, machine translated)
— Description from AniList community (anilist.co).