Honoka's older sister loving her gives me joy, she always seems so...aloof but this time we got to see her more human with emotions and all, even cuddling with Honoka reading stories¡
Then again, it more or less serves to give an explanation for why she's staying with him in the first place; he's a family friend or relative and she had visited him previously. I may be a tad overly invested in the general worldbuilding and continuity in this manga lol
Maybe is a foster type of situation.