Karin/Headscratchers

• Anime: why is biting someone such a big deal? Karin freaks out when biting Kenta or his mother is even mentioned. It's not like there's any adverse effects or anything. I understand it's supposed to be taken as a metaphor for something, but doing "something" to a random stranger or risk losing control is somehow better than a consenting friend? Explain!
  • Only read the manga, but she's just a confused kid and it's all in her head. Even her family flat-out tells her to do it, and HE gets mad and/or disappointed. But with him it's an intimate act; not a biological function. She keeps over-thinking things until it becomes a complex. The most pertinent reason is because she's worried it will progress their relationship, and relationships with humans are considered a taboo.
• The manga's ending. Ok, so the family erased her memory and left Kenta as the Secret Keeper. But what about all of their classmates who knew that Karin had a little sister? What would happen if one of them casually brought her up in a conversation? I mean it's just a huge plot hole.
• What about at the plot whole that the ending left? One of the main reasons to wipe her memory was because she was happy now and didn't need to inject blood to anyone but what would happen when Kenta dies, or their marriage become rocky or have a discussion? She would return to her old self
  • The whole blood giving thing was tied to the spirit of Sophia, who was inhabiting Karin's body in the last iteration. Since Sophia has left Karin's body as Kanon, then Karin's blood making powers are gone as well. Period.
• The anime's ending confuses me. They all bit Victor to rid him of his evil mind- they got rid of his lies, pride, envy, etc. Fair enough. But, as demonstrated with Fumio, don't the effects of vampire bites only last for a set amount of time? After Karin bites her, she's happy and energetic as opposed to sad and depressing, like she usually is, but only for a month or so. Wouldn't Victor eventually revert back to the way he was before?
  • He would, if left to his own devices. But he only became grouchy because of Winner having been bitten by a vampire, and now that he is the same as before the accident but won't see Winner being bitten again, he'll become a better guy.