Summary
If you make 4,817,871,648 円 a year living in Japan, you will be taxed 2,217,316,710 円. That means that your net pay will be 2,600,554,938 円 per year, or 216,712,911 円 per month. Your average tax rate is 46.0% and your marginal tax rate is 46.1%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100 円 in your salary will be taxed 46.10 円, hence, your net pay will only increase by 53.90 円.
Bonus Example
A 1,000 円 bonus will generate an extra 539 円 of net incomes. A 5,000 円 bonus will generate an extra 2,695 円 of net incomes.