In-game Aiko has a corruption meter that can be seen from the 'NPC's' part of the 'Stats' menu.

You have the option of either just giving the ball back peacefully or her 'getting rough' to get it back, which just leads to the typical deals she has for the first encounter. If you are a Nine-tailed Kitsune when you first meet Aiko, a special meeting sequence occurs where she tricks you with an illusion, but then bows and apologizes when she realizes you have nine tails.

Spar ( Exchange some friendly blows The loser must satisfy the winner Both ( *Have a chat then some fun times with foxy Aiko after ) Fun time ( Have some fun times with foxy Aiko ) 'You emerge into a clearing dominated by a familiar, ancient-looking tree, just in time to see a small feral fox with lustrous silver fur', “I’m surprised you managed to find this place again” Corruption ( Activate Aiko's Corruption ) GOTTA TOUCH THEM!!! ) You tell Aiko that you want to rub her tails, how lewd! Fluffy Tail ( Those tails look so fluffy. Fight ( - Only if you chose Yes to fight her in the first place ) ) She will give you a kiss and raises your Strength or Toughness by 3. Nothing ( Give it back, it's hers after all. Sex ( That sexy proposition sounded very enticing. Power ( Can I become even more powerful? ) Causes her to trick you and give a pipe Riches ( GIVE ME ALL THE GOLD!!! ) Causes her to trick you: you are given useless leaves. She wields a longbow almost as tall as she is that she can summon and dismiss with a snap of her fingers, and stares you down with a determined fire in her glittering blue eyes. She sports a number of red “tattoos” adorning her face and body the most prominent of which are the spiral-shaped patterns on her palms and buttocks, and a stylized lotus flower on her lower back. She wears a set of revealing blue and white robes, neatly pressed and hung off her features with care, her D-cup breasts bound by a cloth chest wrap that is just a little too tight. Seven luxurious fox tails sway behind her, the silky fur shimmering as they move. She has a head of short silver-blond hair that ends above her shoulders, parted by two large, furry fox ears.

Coc mod wikia