After rereading this and FINALLY (I think) understanding the ending because I did not get how she survived after she went fully unresponsive, I honestly think it can be interpreted in two different ways:
One, she died and they are in the after life, seeing each other as youngins but actually being old because that’s all they wanted and because he died while going to the island as they were taking it down.
Or, how it actually ended, from my new interpretation (please feel free to correct me I’m still confused) , Shinpei thinks she is dead and is in hardcore denial until he brings her to second ML where, a “BIG MISUNDERSTANDING” happens and shinpei thinks she’s really dead when really she’s just getting treatment and he goes off, initially, back to their little home, and then begins traveling for several decades before he comes back and finds her alive and well and that he just misunderstood but he’s just happy to have her back . ╥﹏╥
I’m going to go with option one and they are both happy in the afterlife where the island isn’t being torn down and they don’t have to deal with waving the island in their old ages and only get a little time with each other. For my mental health.
Thank you for reading this whole thing omg…