[I absolutely hate the fact that "seme" and "uke" made its way into anime and shit. That's disgusting man. Sure, one person could be more dominant than the other, and sure, someone could very well be a submissive person, but the way that it's portrayed is gross and seems so unhealthy and abusive. Dominance and submissiveness are not the same thing as "seme and uke," however.
Let me make something clear.
The terms "seme" and "uke" originate from martial arts, and seme means "attack" or "offense," and the uke is the person who "receives" the attack from the seme.
I remember when I was part of a judo club. Whenever we were practicing techniques, a partner and I would take turns being the seme and the uke so that we could both learn how to protect ourselves from the fall/throw/getting out of a pin, and so that we could learn how to DO the throw and how to put someone in a particular pin.
Taking the definitions of those terms and how they're applied to manga and anime, it's gross. Because in martial arts, you're supposed to let the seme attack you so that you both learn. When you think about it sex wise, the "uke" just lets the "seme" have their way, and I absolutely hate hate hate it. When it comes down to pairings, people argue that a certain person's name should be first in the ship name just because they think they're the "seme" of the two.
Um, no? It doesn't matter what the ship name order is. It's the same ship. Just because you think one character is more dominant than the other, it doesn't mean it makes it a different ship completely.
Anyways, yeah, it's gross how people apply them to ships and not only trash characters and start ship wars and make toxic environments, but they fabricate these completely unhealthy relationships that's completely reliant on one character's dominance and submissiveness. :l Sighs.
I've been seeing a lot of "seme" and "uke" related posts lately, and I thought I would add in my two cents.]