Usotsuki Omega No Kamase Kata summary:

Narumiya an Alpha and a top performer at a trading company, hates his rival Tsukishima, and is passionate on not losing against him. One night, he saw Tsukushima whom he thought was an Alpha in heat?!  A Secret Office Love of an Elite Salaryman (alpha x) and  a beautiful and capable Omega that is hiding a secret♪