Manabu Yasui is a professional shogi player ranked 6-Dan, known for his humble and timid demeanor. While facing an impending divorce, his daughter wished to stay with him until Christmas. On Christmas Day, Yasui competed against Rei Kiriyama in a ranking match. During this game, Yasui made a critical error that shattered his competitive spirit, leading to his defeat. After the match, Rei delivered a Christmas present Yasui's daughter had intentionally left behind. This prompted Yasui to openly confess his personal failings and shortcomings to Rei, an admission that deeply unsettled Rei. Yasui habitually coped with losses through alcohol consumption and gambling, underscoring persistent personal struggles.