Masahiro Nishiki is a veteran bank clerk, working at the Nagahara branch for Tokyo Daiichi Bank. One day, a cash-lost incident takes place at the Nagahara branch. Masahiro chases after the truth behind the cash-lost case with his …

During the reign of the eighth shogun of the Tokugawa shogunate, the Yunagaya Domain in the Tohoku region is a small han. But at the han, there is a gold mine. Suddenly, Masaatsu Naito of Yunagaya Domain receives an order to perform Sankin-kotai within 5 days. Sankin-kotai is a custom that requires the daimyo to visit the shogun in Edo. Unfortunately, the time needed to visit the shogun in Edo for Masaatsu Naito is 8 days. Masaatsu Naito also learns he received the order because a high ranking government official wants the gold mine. Also, the expense for Sankin-kotai is high and the Yunagaya Domain is such a small han that it seems impossible to complete. Nevertheless, Masaatsu Naito begins an unexpected operation to complete Sankin-kotai in 5 days.

One day a puppy comes to the house of Akari, who has just turned twelve, and was trying hard to act strong after her mother suddenly fell ill. She immediately falls in love with the puppy and names it “Socks” after the paws which looked like they had white socks on. Akari was together with Socks day and night. However, as Akari grows up, her feelings and interest moves away from Socks. Year by year, their distance grows, which also leads to her physical distance as she moves to a far off city, and must leave Socks behind to a childhood friend.One day Akari remembers the 10 promises that she had made with Socks and her deceased mother…