He’s Expecting(2012)

Hiyama Kentarou no Ninshin

When career-minded Kentaro Hiyama finds out that he’s pregnant, it will change the course of more than just his own life. In the Japan of Eri Sakai’s thought experiment, ten years have passed since the male sex has spontaneously gained the ability to get pregnant, and society has struggled to adjust. Kentaro isn’t sure at first who the mother might be, and quickly finds himself butting up against regressive attitudes and discriminatory policies—most of which long precede male pregnancy. In his previous life, he’d never given any of it a second thought—he may have even held the same views. But through his encounters with other pregnant people, and galvanized by his new perspective, Kentaro turns his skills in business and marketing to effecting social change.

(Source: Kodansha USA)

Note: Includes 1 extra chapter.