The story begins with Hanabi, a sixth-grade girl who is neither an adult nor a child. She deals with issues such as accidentally witnessing her homeroom teacher kissing, and worrying about experiencing physiological changes before her friends. The series depicts a 12-year-old girl's innocent worries and first love.
12-sai.: Chicchana Mune no Tokimeki (Season 2)

Love Kiss Kiss!? (Episode 1)
Writer: Fumi Tsubota
Air date: 2016-10-03
Runtime: 24 min
Overview: After entering her puberty, Yui Aoi started having pimples on her face, which worries her that because her pimple, Kazuma might not like.

Rival (Episode 2)
Writer: Fumi Tsubota
Air date: 2016-10-10
Runtime: 24 min
Overview: At cram school, Inaba tries to make Yui like him, but in the end she thinks of him as nothing more than a playboy.

Promise (Episode 3)
Writer: Fumi Tsubota
Air date: 2016-10-17
Runtime: 24 min
Overview: Parent's Day is coming up in class 6-2, and a lot of the family members of the students are coming to the class.

Heart (Episode 4)
Writer: Fumi Tsubota
Air date: 2016-10-24
Runtime: 24 min
Overview: Yui helps the girls in her class make wish bracelets, which are bracelets that, if worn by the person you like and yourself, will make the two of you stay together forever.

After the Rain (Episode 5)
Writer: Fumi Tsubota
Air date: 2016-10-31
Runtime: 24 min
Overview: Inaba takes Yui to the fair to cheer her up. He ties her wish bracelet to a balloon and sets it free to symbolize her leaving Kazuma.

Balance (Episode 6)
Writer: Fumi Tsubota
Air date: 2016-11-06
Runtime: 24 min
Overview: Class 6-2 is performing a school play. The play is Cinderella, and Yui is cast as Cinderella and Yuuto as the prince.

One-sided Love (Episode 7)
Writer: Fumi Tsubota
Air date: 2016-11-13
Runtime: 24 min

Friend (Episode 8)
Writer: Fumi Tsubota
Air date: 2016-11-20
Runtime: 24 min

School Trip (Episode 9)
Writer: Fumi Tsubota
Air date: 2016-11-27
Runtime: 24 min

Bye Bye (Episode 10)
Writer: Fumi Tsubota
Air date: 2016-12-04
Runtime: 24 min

Forever (Episode 11)
Writer: Fumi Tsubota
Air date: 2016-12-11
Runtime: 24 min

I Love You (Episode 12)
Writer: Fumi Tsubota
Air date: 2016-12-18
Runtime: 24 min
