@Nanaao When crown prince handed over his letter to one of his person to personally deliver it, I think it is that person who put it in Rosie's book.
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Omegaverse >ω< https://mangamirror.com/manga-list/106967
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Historical BL ♛➛ https://mangamirror.com/manga-list/122136
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Best stories ⛧⁀ https://mangamirror.com/manga-list/106911