  We present a new construction of mirror pairs of Calabi-Yau manifolds by
smoothing normal crossing varieties, consisting of two quasi-Fano manifolds. We
introduce a notion of mirror pairs of quasi-Fano manifolds with anticanonical
Calabi-Yau fibrations using recent conjectures about Landau-Ginzburg models.
Utilizing this notion, we give pairs of normal crossing varieties and show that
the pairs of smoothed Calabi-Yau manifolds satisfy the Hodge number relations
of mirror symmetry. We consider quasi-Fano threefolds that are some blow-ups of
Gorenstein toric Fano threefolds and build 6518 mirror pairs of Calabi-Yau
threefolds, including 79 self-mirrors.
