12-sai

Age 12 (12歳, 12-Sai.) is a Japanese slice of life romance shōjo manga series written and illustrated by Nao Maita. It began serialization in 2012 in Shogakukan's Ciao manga magazine and eight volumes have been published so far. Initially released on animation as an OVA adaptation released in April 2014, it later gained 2 TV series adaptations. The first being an anime split into two seasons, the first half first aired in April, while the second half aired in October 2016. The second was a drama entitled it was also adapted into a video game.

Plot
Hanabi Ayase and her best friend, Yui Aoi, are 6th graders in school. When Hanabi is chosen to work with Yuuto Takao for an upcoming test, she begins to fall in love with him and they both start dating. Yui also falls in love with Kazuma Hiyama, after he protects her from a classmate who talked about Yui behind her back, and they start dating as well. But with physiological changes and more and more obstacles in their love lives, will Hanabi and Yui overcome everything and find true love at the age of 12?

Other Sources

 * MyAnimeList (Manga)
 * MyAnimeList (OVA S1)
 * MyAnimeList (OVA S2)
 * MyAnimeList (TV S1)
 * MyAnimeList (TV S2)