Spoilers, obviously:
Chisato has a rare prototype mechanical heart that can't be replaced. The bad guys sabotaged it so she only has two months to live but she claims it wasn't a big deal because it would stop working when she turned 18 anyway.
No one is sure what happens next, but there is still some hope since the bad guys were trying to bribe her with a new mechanical heart, 2nd last episode is tomorrow but I suspect ep 13 is an epilogue. Wish us luck.
last edited at Sep 17, 2022 12:21AM