Dear CALL

Dear CALL (Dear CALL-ディア コール-, Dia Kōru) is a 2019 Japanese manga series written and illustrated by GUNCHI Kiri.

Plot
On a small island not shown on the map, a boy Sanso lived with a white tiger Moon and a black dog Good. One day, Rindo, a summoner who came from the mainland, tells him that Good is a "black soul" that attacks humans. Rindo then shoots Good, who starts rampaging and starts attacking even Sanso...

Chapters not yet in tankōbon format

 * 4. Teacher