u/Jazzlike_Razzmatazz

So, I read this manga a very long time ago and could only recall a few details from the first chapter. So, basically, the first chapter starts with the MC's sister working at a castle. She returns home to find MC sleeping in his room. They have a bit of sibling bonding but MC is nonchalant and reveals that he fell in love with a girl. The setting is medieval fantasy.

Please help me find this manga!