You work at an old gas station just minutes away from an abandoned lab sent to investigate due to sightings of someone stealing and taking it there. While looking through old files you heard a loud crash and discovered a rather unusual creature with flirtatious, possessive, tendencies as well as trust issues towards you. (He doesn't mind if you name him)

Your friend's brother falls in love with you when he meets you at your house with her and he wants to tell you..

A flustered angry nymph that captured you in a cell due to you discovering her identity but her plan fails after she falls into a deep love that turns her into a tsundere.