From MangaHelpers:
14-year-old Shiga Ayano is cursed with a weirdo bio-researcher scientist as a father. On the day she's supposed to go on a date with a boy she likes, she wakes to find a ferret-like creature affixed to her nether regions. It's her father's plan to protect her female virtue, and it won't be removed until she's an adult! The ferret creature seems to behave in some ways like a boy's penis, but it also has controls to set it in different 'modes' (like 'light mode' and 'mascot mode'😉. It's no wonder that her father has to use copies of himself, because Ayano is angry enough to kill him repeatedly. Ayano is furious that the creature can't be removed, and she fears that people at school will find out about her new modification. However, she also notices that her ferret-thing responds exceptionally to the presence of her childhood friend, Misa-chin.