Semi wa Magic Cube
Japanese title: 세미와 매직큐브
Alternative titles: Semi and the Magic Cube
Type: ONA
Source: Original
Episodes: 26
Status: Finished Airing
Aired: Aug 1, 2018 to Feb 7, 2019
Duration: 13 min per ep
Rating: PG-13 - Teens 13 or older
Studios: Durufix
Genres: Action, Comedy, Fantasy

The story tells the tale of Semi, a bright girl who goes in a magical time journey with the genius teacher Wai, in order to prevent the evil X from utilizing the powers of the magic cube for evil. Along the way, Semi and her math school friends run into history and math problems that they must solve with logic and wit.

(Source: hobbykr)