ROYD-146 My brother's wife and I were supposed to have a kiss-only relationship...but we couldn't stand each other, so we coated each other with saliva and secretly had inseminated sex over and over again. Mei Itsukaichi

'Mei' was starting to drift away from her husband, who was devoted to work. He begins to develop feelings for me, his brother-in-law who lives in the same house, and a forbidden love gradually blooms between the two of them... The two make a ``promise to just kiss'' and begin their ninja love. But my desire doesn't stop. As love and desire intertwine, Mei pours out all her feelings towards me, and even though Mei also has feelings for her husband, in the end they intensely love each other.