Okuchi ga Ecchi na Jakuten datte, Rival no Elite Douryou ni Barete Shimaimashita

Suzuka Takamine has worked at a major business consulting company for three years. At the office, she’s called the unattainable ’Takane no Hana’, because of her work performance and good looks.
But she has a complex. Her mouth is overly sensitive.
When her mouth is stimulated, her body reacts with a jolt and her eyes overflow with tears.
One day, the secret she’s been hiding from everyone is discovered by her colleague; the company’s ace, Kouma Zaizen.
To get caught by her rival, of all people, could have been the end of her, but Takamine’s reaction seems to match Zaizen’s fetish to a T.

”What a sexy expression… So cute. I want to make you cry more.”
He’s a little sadistic and totally infatuated with her, complex and all.