Umibe no Byouin de Kanojo to Hanashita Ikutsuka no Koto
There was a "battle" a year ago. A contagious disease that suddenly hit a rural area? In the mass death of the inhabitants by the population, strange capabilities develop in young people who survived while infected. They will use that ability to fight the variants who appeared at the same time with this disaster.
Note: Place second place in tankoubon category of "Kono Light Novel ga Sugoi 2019".