Spoiler
A school student gets beheaded by the Raven Orphenoch.
The monster deaths are on brand, though
1- Mari's not with the other Ryusei students.
2- Takumi/Mari/Keitaro are introduced in chapter 2, along with a new character who seems to be Mrs. Kikuchi/Keitaro's mom.
3- No sign of Kiba/Yuka/Kaidou.
4- Kusaka's a richie rich living in a expensive apartment with some fangirl, despite Kusaka simping for Mari. He has a backstory:
Spoiler
You're awesome, Kohei Murakami, but this isn't it.