Taking place between the events of Free!: Eternal Summer and Free!: Dive to the Future, Free!: Take Your Marks plays out the graduated seniors' last summer through four different stories before they set sail for the future. Unmei no Choice! (Destined Choice!) follows Haruka Nanase and Makoto Tachibana searching for a new apartment for Haruka as he settles into Tokyo. Hitou no Cooling Down! (Cooling Down at the Secret Hot Spring!) sees Aiichiro Nitori choose a graduation gift for Rin Matsuoka and Sousuke Yamazaki, while Momotaro Mikoshiba wins tickets to the Anago Hot Springs. Hoping for a trip together, Aiichiro and Momotaro invite Rin and Sousuke. Kessoku no Batafurai! (United Butterfly!) shows Rei Ryugazaki, Nagisa Hazuki, and Gou Matsuoka creating a recruitment video to attract new club members for the next school year. Tabidachi no Etanaru Buru! (Departing Eternal Blue!) looks into the Iwatobi and Samezuka swim teams' plans for Rin's surprise going-away party, as he will be departing for Australia soon. [Written by MAL Rewrite]

The show starts with the tale of Chitose Fujinomiya, a girl who goes from riches to rags and back and remains a snob despite it all. When her wealthy father dies, remaining debts leave Chitose almost broke, and she is kicked out of the affluent Tokai no Gakuen, or City Academy. She is left with nothing in the world but the clothes on her back and one pink goldfish named Gyopi-chan, the only memento she has of her father. Wandering lost, she collapses on the grounds of the poor-but-happy Inaka no Chugakko (Country Jr. High School), where the students are rough if friendly, and farm animals regularly roam the school grounds and even attend class. Recovering, she enters into the school but is repelled by its air of poverty, to which she is unaccustomed. (Source: AnimeNfo)

Haruka Nanase has a love for water and a passion for swimming. In elementary school, he competed in and won a relay race with his three friends Rin Matsuoka, Nagisa Hazuki, and Makoto Tachibana. After claiming victory at the tournament, the four friends went their separate ways. Years later, they reunite as high school students; however, Rin couldn't care less about returning to the way things used to be. Not only does he attend a different school, but the sole thing important to him is proving that he is a better swimmer than Haruka. After the bitter reunion, Haruka, Nagisa, and Makoto decide to form the Iwatobi High School Swim Club, but they will need a fourth member if they hope to take part in the upcoming tournament. Enter Rei Ryuugazaki, a former member of the track team whom Nagisa recruits. As the time to compete draws near, the four develop a close bond while training intensely to come out on top and settle things between Haruka and Rin once and for all. [Written by MAL Rewrite]

Chibi Maruko-chan is a shōjo manga series written and illustrated by Momoko Sakura. The series depicts the simple, everyday life of Momoko Sakura, a young girl everyone calls Maruko, and her family in suburban Japan in the year 1974.