chapter 5 being stand alone is kinda lame, but only so much as it starts in the middle of the drama 4 left off, so even when you remember the previous chapters everything feels a lil out of context... if it helps
the reason the oldest sister shows up first in the names age and relationships at very start is because she has been the mom of the house for years, though the mom works to financially support everyone with dad gone, the oldest sister is the one who takes care of everyone.
mom basically knows nothing about the kids personal lives and emotional well being, whether out of ignorance ego guilt of a mix of all, she gets super defensive and over reactive when anyone points this out
the little sister feels abandoned and mistreated by the mom, is emotionally dependant on the MC and older sister.
MC can hypnotize people, and winds up fooling around with lil sis, if i remember correctly that didnt require hypnosis. anyway mom catches them messing around and goes ballistic deciding that to fix everything MC needs to go to military school. no one agrees. the older sister tries to mediate a bit and support the mom since the mom does work hard to financially support, but she also knows the mother has been completely absent of their lives and that sending MC off is ignoring the problem not dealing with it. MC tries to hypno mom into staying, the lil sister starts arguing with mom, hypno isnt failing but also not changing the moms mind.
and then chapter 5 starts when it looks like MC is definitely going away soon and lil sis is at her end of patience with their mother and wants to run away/leave home for good if MC wont be there.
not as good as the lewds and renders of chapters 1-4 but enough basic info where chapter 5 doesnt feel like walking into the middle of shit. seriously i replayed 1-4 last week and still felt like i had no clue what was going in 5. maybe its just me, ive some neuro issues lately that are side effects worse than the ones i was treated for. i could be thinking of a completely different game for all i know, im not, i dont think.