"Let's test ourselves. If we really are each other's 100% perfect lovers," -> overlaps with the scene with Mitsuha and Taki where they exchange the hairtie and drink each other's Kuchikamizake. Age of them being teenagers overlaps too.
Very end where they pass each other in the street (intersect) overlaps with Mitsuha and Taki meeting each other by chance on the train (diff trains going diff ways) and reconvening at the hill (with stairs).