she forces herself on Yuu through half of the story is borderline sexual harassment.
Not like she ask for consent most of the time and Yuu stop her when she goes too far. She had never really forcing herself on Yuu that much beside what ? The first time in the storage before sports day and even there, she ask Yuu if she can kiss her before.
I know that none of it is really sexual harassment, because Yuu does give consent in most occasions. But most of the time it feels like she's just... yielding, due to Touko's insistence. And if you have to insist in order to get consent, isn't it pretty clear that your partner doesn't really want whatever you're asking of them?
And that contract in chapter 10, I think... "Don't fall in love with me or with anyone else." That's a little creepy.
All in all, those things work in the story, because of the way the the plot is built. It's a great story, and there's nothing inherently wrong with Touko's actions there. But if these things were to happen in real life, Touko's behavior would raise a lot of red flags for me.