Kanojo-tachi no X-Day

It's senior year, and Rica is seriously stressed out. She's got more homework, exams, and papers than she can handle, and was recently dumped by her boyfriend. In other words: Life sucks! One day, she's chatting online when she meets three classmates who hate school as much as she does. Together, they hatch a plan to blow up the school when no one is present. The countdown is on for X-Day ...
(Source: Tokyopop)
Note: Includes a side story called Saigo no Bansan (The Last Supper).