English version:
It's probably a bad translation (apart from having some punctuation marks wrong, but please don't give it much importance), since I translated it with Google Translate, but I just couldn't help myself and I wanted more people to know about this certain "headcanon" so to speak that I have about these two, in any case thank you very much if you stopped by this comment and took the time to read it.
I'm here to tell you a certain hypothesis that I came up with when reviewing the title, although it's normal to think that the title is being said by Sheena to Mimi, in my opinion Mimi is the one who says it to Shena, as we saw in previous chapters Ali told Mimi in other words, that even if she gave away Serian's things and she wouldn't be there with them anymore, the memories of the things they did together for so long would never disappear and that's exactly what makes her seem "alive". "the memories of that person keep her alive for you, it's very like coco (the movie), but let me be, I'm happy (it's really still extremely sad to think about it this way, but let me be) so for me Sheena will always be alive even if she passes away and that makes me think that she will love Shena for all eternity.
Okay, I realized some time later that the truly converted title says I will love you until the day you die, I always read it as until the day I die, so my bad, BUT STILL, I will never stop thinking in this certain way, although it could also mean that Sheena will love mimi for all eternity even though she is no longer alive, MEANING THAT THEY LOVE EACH OTHER FOR ALL ETERNITY.
Spanish version:
Les vengo a contar una cierta hipotesis que me plantie al revisar el titulo, aunque es normal pensar que el titulo se lo esta didicando sheena a mimi, a mi parecer mimi es la que se lo dice a Shena, como vimos en caps anteriores Ali le dijo a mimi en otras palabras, que aunque regalara las cosas de Serian y ella ya no estuviera alli con ellos, los recuerdos de las cosas que hicieron durante tanto tiempo juntas nunca iban a desaparecer y eso es exactamente lo que hace parecer que esta "viva" los recuerdos de esa persona la mantiene viva para ti, es muy tipo coco (la pelicula), pero dejame yo soy feliz (realmente sigue siendo extremadamente triste pensarlo de esta forma, pero dejame ser)por lo que para mimi Sheena siempre va a estar viva aunque pase al mas alla y eso me da a pensar que ella va a amar a Shena por toda la eternidad.
Okey, me di de cuenta tiempo despues de que el titulo verdaderamente traducido dice te amare hasta el dia de tu muerte, siempre lo lei como hasta el dia de mi muerte, asi que mala mia, PERO AUN ASI, jamas dejare de pensar de esta cierta forma, aunque tambien podria significar que Sheena amara por toda la eternidad a mimi aunque ya no este vida, OSEA QUE SE AMAN MUTUAMENTE POR TODA LA ETERNIDAD.