The family dynamic gets to its logical extreme mid chapter 7, where immediately after rescuing Sana and Felicia from the fallout of the events of chapter 6, Iroha and Yachiyo have to order the two to stay at home and rest because they had just been through a lot, an it is very difficult to read through that part and not think "Oh, so they are just their parents now, hm?", even if you hadn't picked up on the dynamic before that point.
I do believe this dynamic is completely intentional and it is supported by the anime, where they show that Felicia and Sana actually share a room in the house, not unlike siblings would, while Iroha and Yachiyo have their own rooms.
last edited at Mar 30, 2020 9:09AM