ARIA THE SCARLET AMMO AA

A young girl idolizes the world-renowned S-ranked butei Kanzaki H. Aria and plans to follow in her footsteps. However, her test grades her out as only an E-rank! All is not lost, however, as Aria agrees to give her some pointers. Can Aria help this newcomer become a first-rate butei? — Description from AniList community (anilist.co).