What's the name of the manga with a girl who has two bodyguards? It's a fantasy manga and there's a girl who has two bodyguards who may have been brothers. They spend all of their lives together and even sleep in the same bed.

But then one night one of the two bodyguards kisses the girl in her sleep (which is not allowed) and so one of them confesses and is going to be put to death or punished and it's all very sad until you find out the one who kissed her was actually the other bodyguard and that he knew the other guy would try to defend him and take the blame 

I think the to guards are orphans, also there's some element of magic I think- demons may or may not be involved- I'm not 100% sure on that
Brother bodyguards sleeping in the same bed as a princess ?

It really sounds like Time Stranger Kyoko (Arina Tanemura) to me




Princess Kyoko shares her bed with two brothers guards


   

She has a time base power
It's about people having power like time, flower, dragon
there are some demons too


   she even actually has demon ears...

the brothers are orphans
She has been kissed by one of the brother but thought it was the other one,


   then some revelations made the one who kissed her appart from them (so sad moment for them)

She attends to high school, but not in our modern world, it is a mix-up between ancient/modern/fantasy/sf world
BUT she doesn't use a katana but a talking staff


It's a bright, fun and adorable manga in my opinion