Note 7 - Stockholders' Equity - Nonvested Share Activity (Details) - $ / shares	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Nonvested (in shares)
Nonvested, weighted-average grant-date fair value (in dollars per share)
Granted, options (in shares)	960,000	2,210,000
Granted, weighted-average grant-date fair value (in dollars per share)	$ 1.06
Vested (in shares)	(960,000)
Vested, weighted-average grant-date fair value (in dollars per share)	$ (1.06)
Nonvested (in shares)
Nonvested, weighted-average grant-date fair value (in dollars per share)