La Vie en Rose (2005)

Blurb:
Fujimori is an up-and-coming novelist whose debut skyrocketed him to the top of the bestseller’s list, but a year later, he’s suffering from a case of performance anxiety... err, writer’s block. The fans are demanding a sequel to Fujimori’s first romantic tale. How can he explain to them that this work of “fiction” was really all about an unrequited love toward his best friend Yoshizumi—who’s actually a guy?! Will Fujimori be able to write his happy ending?

Source: www.anisearch.com/manga/45