12-Sai.: Kiss, Kirai, Suki Age 12: Kiss, Hate, Love
The story begins with Hanahi, 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 manga depicts a 12-year-old girl's innocent worries and first love.
[Source: Anime News Network]