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...

Iku (Nana Eikura) joined the Library Defense Force after a member from that team retrieved an important book that was targeted for censorship. She is assigned to work under Atsushi’s (Junichi Okada) team. She endures Atsushi's harsh treatment and looks for the member who retrieved her book. She also finds herself becoming attracted to Atsushi. Iku meets female high school student Marie (Tao Tsuchiya) at the library. Maries has a hearing disability. She is also a childhood friend of Mikihisa (Kei Tanaka). Iku senses Marie’s strong feelings for Mikihisa. Asako (Chiaki Kuriyama) works as a clerk for the Library Task Force. She has frequent meetings with curator Shuji (Aoi Nakamura). This creates complicated feelings for Hikaru (Sota Fukushi). One day, Mikihisa is arrested because of a book he recommended to Marie. Official reason given is because the book is unsuitable for disabled people. The members of the Library Task Force are angered by Mikihisa's arrest.

16-year-old Haruka lost the people she loved the most in a fire. Haruka is also physically and emotionally wounded from the fire, but she still dreams of becoming a pianist. She takes part in an upcoming competition. Inauspicious incidents then occur around her. Musical student Yosuke, who teaches piano to Haruka, tries to solve the case.