Sayaka Minami works as a designer for a company. She is 30 years old, single and has not had any love experience due to her 15-year unrequited love for Ryosuke Sagisawa. They have been friends since they were kids. One day, Sayaka wakes up and a strange man is in front of her. She panics and the man introduces herself as Shohei Machida. He works as a salesman at the same company as Sayaka. He tells her that they are in a relationship and live together. Sayaka lost her memory for 3 months.