0:42 - Yeah, Assmo messed up the text on this screen. The text should read "I played with Yukito-san today. It was really fun." And the fish is saying "You can't catch me!"

21:32 - Kanna's using the royal "we," the way a royal person refers to himself or herself.

21:35 - 正八位衛門大志 (Shouhachiigesaimonnodaisakan) is Ryuuya's military title, ranked 7th from the bottom out of 28 "ranks." His main job is to oversee the guards at one of the palace gates.