Brain guy is probably based on the Brain Puffball (Calvatia Craniiformis).
This manga goes deep into obscure mushroom references, especially Asian species.
I think something is lost in translation?
My understanding is the guy wants her to act like a tsundere with him like she does to others. But only gets the dere part, because she loves him too much and is too self-aware of her tsun side.
Well...
That's a big... jump.
At least I understand why I didn't see any releases for two years.
Some dragon was hoarding the chapters! Until some adventurer managed to snatch chp 105 and so forth.
Ah! Phew...
For a moment I thought we wouldn't be able to witness a 100-feet tsunami level calamity happening as a consequence of Hana's idea.
I'll see myself on an elevated location with a bag of popcorn and a canoe.
Now that I think about it : Dad (feared OP hero); Mom (Great Dragon); Sister 1 (Demonlord daughter); Sister 2 (Artificial hero)...
Everyone very OP, very outcast, very... not "normal."
This feels like a fantasy version of an Addams Family!
Started like a comedy. Ended in horror.
Love it.
Reminds me of that reddit post going like :
"I have the power to hear the sounds from one year in the future.
Today, the noise stopped."