Kyouai shinu made ni shitai yon-tsu no koto (2005)

Miwa is informed that her time is limited due to heart disease. Submitting a letter of resignation to her workplace, she says goodbye to her boyfriend Shinji, afraid of becoming a burden to him. Throwing off Shinji's hand, Miwa sets off on a lonely journey. The one who comforts the brokenhearted Shinji is his colleague, Kyoko. Soon, the two fall for each other and become lovers. Learning of their relationship, Miwa goes mad with jealousy. She tries to trap Shinji with whatever means she can. Becoming a stalker, Miwa persistently corners Shinji and Kyoko. How far will she go?