Usagi ga Nihiki
兎が二匹
A woman who has lived for 398 years possesses the ability to never die. Each day, she enlists the help of her 19-year-old live-in partner to attempt suicide, but he consistently convinces her to stay alive. Despite repeated failures, she continues to seek a way to end her life. One day, overwhelmed by painful recollections, she discovers what she believes to be a definitive method. As their relationship evolves, the gap between them widens even as their emotional bond strengthens.