Ueno-san wa Bukiyou

The story centers on Ueno, a genius inventor who is in the third grade at her junior high school. She also serves as the head of the school's science club and secretly falls in love with one of its members, second grade student Tanaka. Using her eccentric inventions, Ueno tries to confess her love to him indirectly. But her attempts always end in failure.
(Source: Crunchyroll)