Story
The story of Kodomo no Jikan is centered around 23-year-old Aoki Daisuke, who has just landed his first teaching job as a grade school teacher at Futatsubashi Elementary School. He is placed in charge of Class 3-1, where one of his students, a mischievously precocious Rin Kokonoe, develops a crush on him and goes so far as to proclaim herself Aoki's girlfriend.
Synopsis via AniList (English).