Usagi wa Kemono no Hara no Soko de Shiawase na Yume wo Miru

Aa school romance fantasy starring Usagi, a high school girl who lost her mother at a young age and struggles to be accepted by her new family. The story begins one day when Usagi stays behind at school to help prepare for the school festival, and happens upon three prominent classmates - Yuuko Masamune, Sekirou Yakki, and Kumayoshi Shino - fighting someone.

(Source: Natalie, translated)