The move comes after Tohoku Shinkansen services were suspended for about a month due to a magnitude 7.4 quake hitting the country's northeast in March.
The system's development is expected to reach its final stages once the tests end, with carriage improvements slated from around spring 2023 to achieve the targeted 2028 implementation.
The surge in seat reservations during the period between April 28 and May 8 has come mainly because the government fully lifted its coronavirus quasi-emergency last month.
Efforts to restore infrastructure are still underway, the company said, and bullet trains will operate at a reduced speed and on temporary timetables for the time being.