Monokuma has a new motive; One student will be split up into 5 different personalities. If one of the personalities get killed, all of them do. (Including the original person)
This student happens to be Ishimaru, his personalities being;
Lust (Purple)
Anger (Red)
Happiness (Yellow)
Sadness/Paranoia (Blue)
Numbness (Gray)
Mondo is assigned with watching all of them, as he knows Ishimaru the best.
During their time together, Mondo learns a lot about Taka he didn't originally know. (Including Ishimaru's crush on him)
After someone kills somebody (That not being Ishimaru) Taka goes back to normal as one human, and he forgets what those personalities said to Mondo.
Mondo doesn't tell Ishimaru about the things they said, but still remembers the things pretty clearly.
Credit me if you use this idea!