its not anime but there’s a tiktok series by an artist named aj called bittersweet, its about two guys in 1950s-1960s new york who get off on the wrong foot but slowly fall in love with each other as the series progresses. the episodes are not at all short (newer ones especially, being around 30 ish minutes) and its definitely worth checking out if you’re looking for doomed yaoi

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The summer hikaru died (horror aspects tho)

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not an anime, it's chinese, but it's called Grandmaster of Demonic Cultivation/Mo Dao Zu Shi. has a comic, anime(called a manhwa), and a really shitty live action. the plot is literally just doomed yaoi from start to finish and it's lowk so gas

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