The Moon is Reborn

Sora Mond is a baby-faced 21 year old, who still goes to Junior High School. Actually, that's incorrect. Sora Mond is a baby-faced 21 year old assassin, known as 'The Moon'. When she finds out that some alien has blown up the moon, the government notifies her and sends her to Kunugigaoka Junior High School to help the Class-E students assassinate the beast. Will the class succeed with the new arrival?