My favorites

Uke is a gangster son but wants to live normal. But uke isn't some pushover and can phunch if needed. Seme turns into his bodyguard. He's quite vulgar and is lusting after uke from the start

There is war happening and in the original timeline, the uke (who is a duke) fled his castle but all his attendants were killed and he was left in the streets startving. He came back in time, didn't flee and has become much more involved in rulling his land and caring for the poor

Seme is a dream demon. Gets food/energy from nightmares and uke has 100% chance of having bad dreams