Timeline

Love at First Sight: Kana falls in love with Leo at first sight

Merged in Body: After Leo dies, Kana lies with his body as a last chance to be close with him. She ends up merged into his body

Adjusting: Leo-Kana try to adjust to their situation

Poisoning: Keisuke appears and tries to seduce Leo-Kana

Losing Grip: Leo-Kana falls deeper into the poison