Once Upon a Witch's Death, Vol, 1 (manga)

Meg Raspberry lives a charmed life in the English countryside as an apprentice to the powerful witch Faust. That is, until her seventeenth birthday rolls around, and Faust reveals that Meg will die in a year from the Death Sentence curse! There’s only one way to avoid her inevitable demise—collect a thousand tears of joy to create a Seed of Life, which will grant Meg immortality. But can Meg still find joy in her circumstances? She might have to learn how anyway…The clock is ticking, and this deadline has no extensions!