We classify the 3-manifolds obtained as the preimages of arcs on the plane for simplified (2, 0)-trisection maps, which we call vertical 3-manifolds. Such a 3-manifold is a connected sum of a 6-tuple of vertical 3-manifolds over specific 6 arcs. Consequently, we show that each of the 6-tuples determines the source 4-manifold uniquely up to orientation reversing diffeomorphisms. We also show that, in contrast to the fact that summands of vertical 3-manifolds of simplified (2, 0)-trisection maps are lens spaces, there exist infinitely many simplified (2, 0)-4-section maps that admit hyperbolic vertical 3-manifolds.