The story is set at Myoujou Academy, a private girls' boarding school. The 10th year's Kurogumi class has 12 assassins with their sights on one target, Haru Ichinose. Tokaku Azuma is a recent transfer student who is also targeting Ichinose, but she gradually develops feelings for Ichinose.
(Source: Anime News Network)
Haru IchinoseMain
Tokaku AzumaMain
Mahiru BanbaSupporting
Sumireko HanabusaSupporting
Nio HashiriSupporting
Isuke InukaiSupporting
KaibaSupporting
Kouko KaminagaSupporting
Shiena KenmochiSupporting
Hitsugi KirigayaSupporting
Ataru MizorogiSupporting
Chitaru NamatameSupportingAniList supplies these relationships. Prequels and sequels connect the story; they do not establish a complete viewing order. Adaptations and source manga are separate works, without an assumed Episode-to-Chapter match.
