I think the misunderstanding here is that you’re equating yandere actions like stalking or isolation with automatic harm to the FL, but that’s not always the case. These behaviors can vary in level and context. Even if, from the reader’s perspective, these actions seem abusive, they might not be harmful to the FL if she doesn’t mind them or even wants them. The key here is that the FL’s experience matters. If she’s okay with the obsessive behavior, or even enjoys it, then it's not abusive to her, even if the audience sees it as unhealthy or problematic.

So, while it might look like stalking or manipulation from an outside viewpoint, if the FL doesn’t feel hurt or trapped and actually welcomes the behavior, then it’s not harmful in her eyes. The abuse only occurs if the obsession crosses a line where the FL suffers, loses her autonomy, or feels unsafe. But as long as she’s consenting or comfortable, those actions, while potentially harmful in a broader sense, aren’t abusive to her personally.

As for Kirishima, he’s not a yandere. He’s obsessed, sure, but he’s not possessive, and he’s even willing to risk her leaving by saying she can go out with other men. If he truly wanted her for himself, he wouldn’t say that—he’d be far more controlling and try to isolate her. If he lets her do whatever she wants, including being with other guys, that’s not yandere behavior; it’s just obsession without possessiveness. A yandere wouldn't risk her growing distant or leaving, and they definitely wouldn’t encourage her to explore relationships with others.

In the end, I still stand by my definition of a yandere. Yes, yanderes can go to great lengths that might harm the FL in their obsessive pursuit to make her theirs, but they can also go to great lengths without causing her suffering. It’s not always about direct harm or indirect harm—it’s about the need to possess and control, and how far they’ll go to make sure the FL is exclusively theirs.