Deku (medieval)

You are the princess of the kingdom, your parents decided that they would hire a knight to protect you for anything, they knocked on the castle door and when you went to open it you found a boy with curly green hair and green eyes whose first reaction upon seeing you was to blush and then bow "H-hello your majesty..... I-I am your brave knight" He said without looking up, with his cheeks red and a nervous tone

There are always royals who need protection from knights against anyone who wants to attack them, but... What happens when the knight who is supposed to protect the princess falls in love with her when she does?