After Natsuki left Miku felt a bit tired because those 3 played video games for the entire day they also studied for a little while and Miku actually was super tired after all that but.
Miku: that was fun though i still couldn't believe you became friends with Mizutani-san, Onii-chan. Uh Onii-chan? Hello?
Kaneki was completely frozen.
Miku: what's going on you were fine just now
Kaneki: sorry about that sister I have some stuff to do I'll see you tomorrow.
What? Onii-chan has gone to his usual self again what happened?
Kaneki: I'll cook dinner later if you need me I'll be in my basement.
Miku: oh.. ok(what happened just now? he was just fine earlier maybe it's because he remembered how i hurt him)
Kaneki: well see you later.
Kaneki went to his basement and Miku went to her room confused but what she didn't know was what was happening in Kaneki's head.
???: hmm that was fun it was like the old days.
???: yeah! it was fun playing with Miku-chan!
???: well we had no choice but I have to admit those smiles they had were really precious we must protect them no matter what!
???: you're right me or Kozo.
???: yeah I agree with you Shitsuren.
Shitsuren: yeah thank you Quan.
???: well if we want to protect them let's watch over Natsuki-san till she gets home.
Quan: hehe I'm the boss Tomo.
Kozo: finally a day where im not arguing with myself
Tomo: yeah i hated my guts but this time is a temporary alliance, i split my one personality into 4 so i can do specific tasks and to avoid those 3 honestly really sad but let's go it's almost night, i must wear that mask again.
Shitsuren: honestly it's a pain but time for the temporary return of the Hero.
there were 4 personas in Kaneki's head and these personas are the result of Kaneki splitting them to do a specific task each. and each of them represents 4 of Kaneki's friends
Kozo has a child like body this persona does research and collects data he represents *****.
Shitsuren a negative and hot tempered persona who despite his nature is actually caring and always worries about his friends he represents *****.
Tomo like Kozo has a child-like body he acts like a brother he represents ****.
and last Quan has a girl like body he helps others when they are down she represents ***** and the reason why Quan has a girl like body is because when the 4 personalities were only Kaneki he spent most of his time with 4 girls so he somehow it influenced his personality.
when Kaneki is alone, his personality sometimes splits because they never get along at all but in rare occasions they agree on something and don't argue.
he split his personality into 4 because he needs to do specific tasks? no! he did it so his former friends would avoid him that's where Shitsuren comes in he was the dominant one since the entrance of high school.
but all 4 decided to be Kaneki when they are around people they know and only split when he is alone.
and right now Quan is in control.
Kaneki/Quan: alright time to change my voice.
T-test T-test testing.
Kaneki/Quan: good now where's my mask? oh there it is.
Kaneki or Quan took the Mask and wore it and left the house.
Sword-san: [which one are you now Kaneki-chan?]
Kaneki/Quan: I am Quan.
Sword-san: [I see...]
Kaneki/Quan: Demon Knight arts, Demon Portals.
after opening the portals Kaneki left the house and ended up at a rooftop of a house where Natsuki is at.
Kaneki/Quan: there you are. wait why is Yuu-chan here?
but he saw Yuuka which made him curious