Tax for city hall and the prefecture, on the previous year's income, at about 10%. It is charged from June to May to people who lived in Japan on January 1.
On your payslip, or on payment slips that arrive in June.
In your first year in Japan there is no bill. In your second year it arrives. If you are leaving Japan, pay what is left or name a tax representative (納税管理人).
General explanation, for guidance. Rules and amounts change: confirm with the responsible office.