The seme should be straight (at last at the beginning) and really reluctant to "swing the other way".It could even be that he doesn't like the uke that much (even hates) at first and afterwards has a really hard time to admit to his feeling.

The uke can be either gay, bi or straight.

BONUS POINTS if the uke is (really) manly!

BUT I do want a happy ending! No tragedy, BDSM, disturbing content, etc.

Thanks !