Dazai and Chuuya

(This is the Middle Ages, the time of knights, princesses, and everything else)
Dazai and Chuuya are from two feuding families, and they were taught to hate each other from childhood, but they genuinely did not understand why.
Chuya was always kept locked up in the castle and not allowed out, and then one day he got tired of it and at night he ran away into the forest nearby. There he climbed a tree to look around, when suddenly someone called out to him
...: Hey, what are you doing there? Be careful, you'll fall!
and Chuuya actually slipped off the branch and fell... right on top of the enemy family's heir, Osamu Dazai
(here they are 11)

Chuuya doesn't snap or get angry at Dazai's displays of affection or care, but he often gets embarrassed.
Dazai doesn't act coldly towards Chuuya.