More than half of nearby disc galaxies have pseudobulges , instead of classical bulges that are though to be end-products of galaxy mergers .
Pseudobulges are presumed to develop over time as a result of secular evolution of galaxy discs .
We report simulations of galaxy formation , in which two disc galaxies with disky pseudobulges have formed .
Based on the profile decomposition , the bulge-to-total mass ratio of the simulated galaxies is 0.6 for one galaxy and 0.3 for the other .
We find that the main formation mechanism of the pseudobulges in our simulations is not the secular evolution of discs but high-redshift starbursts .
The progenitors of the pseudobulges form as high-redshift discs with small scale lengths by rapid supply of low angular momentum gas .
By redshift 2 , before the main disc formation , pseudobulge formation has largely completed in terms of mass .
The secular evolution such as bar instability accounts for about 30 % of the bulge mass for one galaxy and only \sim 13 % for the other but does affect the final shape and kinematic properties of the pseudobulges .