Midara na Omega wa Kawaiku Naku

"The pleasure you feel when you give in to your instincts is incredible, isn't it? Go on... try moving your hips yourself."
Shigasaki Subaru is the company's elite top salesman. Although he's an Undifferentiated, belonging to neither the Alpha, Beta, nor Omega secondary genders, he's more than capable of holding his own against the Alphas.
One day, he meets Satou Haruki, a newly hired Alpha employee. To Shigasaki's shock, despite supposedly being Undifferentiated, he suddenly goes into heat and transforms into an Omega.
"So you were an Omega all along, Shigasaki-san! And here you were, acting all high and mighty alongside the Alphas in Sales!"
"Those pheromones are incredible... It's like you're begging to be taken."
Before he can make sense of what's happening, Shigasaki finds himself targeted by the unchecked desires of the Alpha coworkers around him...

(Source: CMOA, translated)