The Nagahara Branch of Tokyo Daiichi Bank is a small branch whose customers are mainly from SMEs. Despite it being a small branch, it consists of a variety of unique individuals who do their best to work together. One day, one million yen in cash is lost at the Nagahara branch. A female bank employee is suspected as the culprit, but Masahiro Nishiki, the deputy manager, who was supposed to be pursuing the case, disappears. What actually happened and what is the surprising truth behind Masahiro's disappearance?