This is kind of a sad start but it was, in my opinion, a really good anime.

"The year is 2021. An unexpected and highly parasitic virus has devastated human society. The virus, known only as "Gastrea", has driven humans into massive walled cities. The only thing that is capable of withholding the virus infected monsters is a metal called Varanium. The city walls and the weapons mankind uses to fight against these monsters are made of it. Despite efforts to keep "Gastrea" at bay, children were soon born with the virus already inside of them. Children born with the virus were called "Cursed Children", were only female and had special powers which humanity deemed as their best weapon to fight against Gastrea monsters. Every team sent out to help fight the virus is composed of Initiators, who are Cursed Children, and a Promoter, who is there to guide and protect them. Black Bullet focuses on Rentaro Satomi, a second year high school student and Promoter along with Initiator Enju Aihara, who is like a sister to him. Together they carry out missions for Tendo Civil Security until one day they receive a secret mission to prevent the destruction of Tokyo area from Gastrea invasion."
- my anime list

Key words:
- two people, girl is one of the cursed children and guy is basically the chaperone
- their job: killing Gastrea
- evil masked guy is spotted in a room full of blood ( human blood ) makes a scene and goes away
- mission update: prevent the destruction of Tokyo area from Gastrea invasion.

The cursed children are oppressed by society and that is one of the facts that makes this anime so sad cause they're so cute and they are fighting for the humans so they should at least show some gratitude

Some secrets about the chaperone and his non-discriminating behavior towards the cursed children and the...
Never mind spoilers

So basically the plot is good
Ups and downs are good
Should I rate this in stars?
Oh well the thing is it has a fairly good chance of appealing to someone that's there for the plot.