Formation of a large in-plane nuclear field Bn under transverse magnetic fields, known as the anomalous Hanle effect, was studied comprehensively in a single quantum dot. From the time-resolved measurements, the buildup time of the in-plane Bn was revealed. Further, the impact of the sign inversion of longitudinal Bn exhibited discrepancies between experiments and calculations, which led us to reconsider the previously proposed model. The newly developed model successfully explained the experimental data, and it suggests that the anomalous Hanle effect is an indication of a large distribution of principal axis of nuclear quadrupole interaction.