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.