hmnn it could be like that? I know in Japanes culture this type of weird romance relation tends to be more... digestable, mainly in fiction/media.
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from how i see it, aoi genuinely loved sakura, but the emotional damage he got from his situation with the bullying and his father at the time was too much for him-- hence the letter and suicide. as a ghost, i think he still hcared for sakura, but the majority of his feelings were suppressed from trauma. one may even argue that his affections for sakura to begin with were the result of sakura being the sole person in his life aoi could rely on for emotional support, but i dont know if i wanna go on that tangent rn lmao.
in any case, kokoroten was going for a feeling of "these two were bound by fate" with aoi and hinata's meeting. in the VN at least i'd say that hinata is the canon interest. to begin with (i was reading up on some of their blog posts and tweets), the game's primary focus is on the development of each of its 4 main characters and how they deal/cope with their past regrets. romance, while apparent, can easily be passed off as bad coping mechanisms and unhealthy attatchments depending on the route ending you play. i believe the reason hinata is the 'true end' is because his status as someone with ties to aoi's past; in fact, the gap in treatment he received from kanata as opposed to how aoi was treated makes him the perfect juxtapostition of aoi. while aoi had romantic interests in akane, sakura's personality and how he grew up may not have made the 'perfect storm' for aoi to finally be forced to deal with the truth of his life and death. if hinata hadn't showed up at the school looking for akane and the lemures blue to begin with, i feel as though not a single thing would have changed.
so TLDR; i think hinata is the true end because the circumstances revolving him and aoi force aoi to face his past and learn about that Sweet Family History(tm) and finally pass on
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and yeah!! i just recently downloaded the free trial for World Downfall Our Imaginary! Vampel (if i have the title right), which kokoroten did the art for, is also available to play online for free- in Japanense, of course