Reaching a period of life where they are neither a child nor an adult, 12-year-old Hanabi Ayase and Aoi Yui meet with life-changing events. Due to the mischievous demeanor of her male classmates, Ayase does not think highly of the opposite sex. However, her perspective begins to change after she is paired with the kind-hearted Takao Yuuto for a class assignment and unexpectedly shared their first kisses with each other on the school rooftop. With her best friend discovering love, Aoi yearns to seek her own. She finds herself falling in love with the rash Kazuma Hiyama after protecting her from a rejected suitor who had talked behind her back. 12-sai.: Chicchana Mune no Tokimeki follows the four in this phase of adolescence. As they grow up alongside each other, this sweet romance depicts the innocence and excitement of first love. [Written by MAL Rewrite]

In the 21st century, the rapid development of the human society has broken the equilibrium between the realms of human, immortal and monster. Su Moting is an ordinary working girl living in the human world. She is also the "son of the immortal and the monster". Driven away from home by her parents, Su teams up with an immortal and a monster, and the three of them start their hilarious daily life.

Rifle-shooting sports are competitive activities testing accuracy and precision using a rifle. In Japan, carrying firearms is prohibited, so most of the participants are members of the defense force. When the use of rifles using a light beam instead of real bullets as ammunition became common, rifle-shooting competitions became accessible to the younger population, giving way to school contests. First-year high school student and marksmanship enthusiast Hikari Kokura has just transferred to Chidori High School. She tries to join the club of her choice, but finds out that the club no longer exists due to the low popularity of the sport. Distraught, she tries to restore the club and somehow manages to recruit three other members: her childhood friend Izumi Shibusawa, the half-Russian Erika Meinohama, and the stoic Yukio Igarashi. This marks the beginning of the Chidori Rifle-Shooting Club, who have only one goal—to compete on the national stage! [Written by MAL Rewrite]

With his mother taken away from him and having lost everything, Lag Seeing is now a letter whose delivery has been assigned to Gauche Suede, a Letter Bee. Despite their troubling start, the two of them become friends, leading Lag to realize what his aim in life is: to deliver people's most important feelings in the form of letters, just as Gauche has done. [Written by MAL Rewrite]