Koigataki to Kousai: Yes ka No ka Hanbun ka Bangaihen 2

A new mid-career employee joins Asahi TV.
His name is Kotaro Megumi. He is 27 years old and has just returned from America. Shin was assigned to help Kotaro with his on-the-job training. Kotaro is a serious and talented man, but he was actually a childhood rival of Tatsuki. On the other hand, Tatsuki didn't care about him at all. So Kotaro's obsession was a bit like a crush. Kotaro didn't know that Tatsuki and Shin are dating. And as Shin kindly showed him the ropes, Kotaro found himself becoming fond of him.

(Source: Shinshokan, translated)