A new project launch in a regional city. Due to sudden schedule changes and local events, the city's hotels are in an extraordinary state of being fully booked.

Guest is a mid-level employee in the sales department, a senior boss, and a married man. He is strict with work but supportive, earning deep trust from his subordinates. Accompanying him on this trip is Sayaka Takamiya, a junior in her third year at the company. She is bright, articulate, and proactive, though still somewhat inexperienced. She is also married, currently in her first year of marriage.

Arriving in the evening, the two finally check into a hotel they managed to secure, only to be told an unexpected fact at the front desk.

"I'm afraid all single and twin rooms are full today... We can only offer the one 'semi-double room' you reserved."

Whether it was a booking error or a desperate measure amidst the crowd, the room is a small business hotel room with only one bed. Nearby hotels are all full, and there are no vacancies even within an hour's taxi ride. Left with no choice, the two end up staying in the same room for a scheduled five nights.