The Saint's Legacy

Having become an orphan, Nae Katamine falls into a "sanctuary" in another world through a wardrobe inherited from her grandmother. There, she encounters a wounded boy named Sacred. Declared a "saint," Nae cannot leave him alone and travels back and forth between the two worlds. However, as time flows differently and their relationship deepens as he grows rapidly with each meeting, a misunderstanding causes them to drift apart, and before they can reconcile, the wardrobe loses its connection to the other world...

Original JP: cmoa