Eren the Southpaw

Kouichi Asakura works as a designer at an advertising agency. Even though he works very hard, he does not receive recognition at his job. Frustrated by his circumstances, he decides to visit a place from his school days, involving Eren Yamagishi.

Meanwhile, Eren Yamagishi has the nickname "Hidarikiki" ("The Southpaw") and is a painter in New York. She is gifted as a painter, but due to her genius-like talent, she suffers.

(Source: MyDramaList)

Based on "Hidarikiki no Eren".
The main character of the story is Ryoma Kobayashi, who works as a new employee at Moonlight, a major entertainment agency. Kobayashi, who participates in a new idol group project by Moonlight, is tasked with shooting the audition making footage. There, Kobayashi came to know the "real of idol business".(Source: natalie.mu, translated)