Summer is the most memorable time in the lives of Mizuno's brother and sister-in-law because it is a memory and also a milestone that completely changes the relationship between the two. That summer, because the company was moving to a location near his younger brother's house, his older brother asked to stay at his brother's house for a while to stabilize and make travel easier. Here, he accidentally fell in love with his sister-in-law because she was not only beautiful and good at housework but also understood men's psychology very well. Even though he knew that this was his brother's wife, he always tried to encourage him to ignore that thought, but day by day she became more and more sexy and arousing in front of him by wearing very provocative and even provocative clothes. Not even wearing a bra. This made him unable to control himself and went over the limit with her on the day his younger brother was not at home. Although he was the one who committed the wrong act first, he knew that his sister-in-law had also secretly loved him for a long time, her love had been given to him since he moved here. Since then, because they didn't want their younger brother to be sad and disappointed, the two decided to keep this secret, burying the secret love affairs they both had in their memories.