That pairing, regarding XX

Kotohira Sakiko is a fujoshi who immerses herself in BL drama while riding the train to work. She especially likes Reiji-sama, a seme character in a BL relationship in a popular drama named "Playing with Fire in the Labyrinth." At work, she's careful to hide this predilection until the she accidentally runs into the company president's son, Utatsu Masayuki, and passes out. Upon waking, she discovers that this perfect man looks just like her Reiji-sama and calls him out with the seme character's name!

Utatsu on his part is secretly terrified because he has always had problems dealing with women who predatorily target him for his looks and his wealth. Surely, he thinks, that Sakiko is a harmless pure maiden perfect for him to graduate his virgin status...

So a strange relationship starts where Sakiko thinks Utatsu will dress up in Reiji-sama cosplay and act out her BL fantasies, and Utatsu thinking that Sakiko is the answer to his fear of women.