Tsui No Sora

Minakami Yukito is our generic protagonist going to school with his osananajimi Wakatsuki Kotomi. However, upon arriving at school on Monday, July 13th, they discover that the previous day their classmate Takashima Sakuro had committed suicide.

Yukito Minakami is awakened by his childhood friend Kotomi for school, but when they arrive there, they find that a female classmate jumped off the roof of the school the day before. Before long, all their classmates are talking about the approaching end of the world on the 20th day

Enter Zaruko Before her death

Enter Yasuko Yokoyama

We Gain a Glimpse into the mind of the cult leader Mamiya Takuji