Kosaka Kei works as a programmer for IT company Spiral. The Tokyo Central Stock Exchange is about to overhaul their financial security system for the first time since their company was founded. The stock exchange will take bids for the work. Spiral is one of the companies taking part in the competition for the winning contract. Hamamura Hitomi is a new employee at Tokyo Central Stock Exchange. She receives training in the information system department. She meets Kosaka Kei and they take interest in each other.