The culprit is Kinji Ogawara. Naoto Kishitani indirectly caused Ryoichiro's death. After the case, Rum detects Rumi and plans to have Chianti and Korn eliminate her.
Rum seventeen years ago.
In the flashback, Haneda headed to Amanda's room and the true name of Asaka was "Rachel Asaka". He also pointed out that the disease of her eye is Amaurosis Fugax.
Amanda and Rum met when he was still a child. Rum said who got that codename from his late father. Amanda swallowed APTX in order to protect Asaka. Haneda hid Asaka and told Rum who saw a piece of news including him gave a speech for Renya Karasuma thirty years ago. Rum decided to kill him.
Haneda left the dying message "CARASUMA" before his death. A car accident happened to Kuroda when he was trying to protect Asaka from the Black Organization. He passed out, but Asaka managed to escape.