Good for Mariya. She can scare off stalkers with her shotgun.
It's unfortunate that Japan only allows its citizens shotguns, and nothing other than that. Shotguns are powerful at close range, but not very accurate, even when shooting slugs instead of shot. Plus, the recoil on 12 gauge shotguns is punishing to the shoulder. (Mariya looks like she has a 12 gauge shotgun there.)