The Tokise High School Koto Club has courageously pushed through their fractured and unsynchronized performance at the Kanto Region Traditional Japanese Music Festival. Club members Chika Kudou, Satowa Houzuki, Takezou Kurata, Hiro Kurusu, Kouta Mizuhara, Saneyasu Adachi, and Michitaka Sakai are devastated to learn the negative results of their performance, leaving them crushed. Nonetheless, the group recognizes their potential and enthusiastically agree to collectively sharpen their skills, improve their flaws, and develop higher caliber playing to succeed in the upcoming national qualifiers in winter. With the help of their now willing club advisor Suzuka Takinami, the group's goal gradually becomes achievable as they begin to grasp the foundations of good music and refine their koto-playing abilities, with the suggestion of performing more often to gain what they lack most—experience. However, as their journey to nationals is underway, the koto club members face challenges that obstruct their focus and progress. Not only does the threat of other powerhouse schools and musicians remain, but the high school issues of budding romance and soon-to-be-graduating seniors also begin to push the limits of the determined group of teenagers and the future of the koto club.

Suzu Urano is a pure and kindhearted girl who loves to draw and keep her head in the clouds. Growing up in the outskirts of Hiroshima with her family, she is more than happy to help with her grandmother's nori business. However, when she becomes of age, Suzu leaves her beloved home to marry Shuusaku Houjou, a man she barely knows. As she integrates into her new husband's household, the homesick bride struggles to adjust to the unfamiliar environment as the war effort extends far beyond its point of no return. When the war reaches Suzu's own backyard and peace gives way to brutality, how will she support herself and those she comes to love along the way? Kono Sekai no Katasumi ni paints a colorful yet haunting depiction of everyday life in the years before and after World War II, showcasing the perseverance and fortitude of ordinary Japanese during one of the darkest periods of modern history.

Gen Kudou, a koto maker, believes that his delinquent grandson Chika would never understand the profoundness of the traditional musical instrument. In an attempt to make up for his naivety and understand the words of his late grandfather, Chika tries to join the Tokise High School Koto Club. Even though the club is in dire need of members, new club president Takezou Kurata is unwilling to easily accept Chika's application due to his bad reputation. Nonetheless, after seeing Chika's seriousness and enthusiasm, Takezou allows the problem child to join, along with koto prodigy Satowa Houzuki and three of Chika's energetic friends. Kono Oto Tomare! follows the merry band of musicians as they aspire to play at the national competition.

Unaired episode included with the third Blu-ray volume.