Note 3 - Long-term Borrowings (Details Textual) - USD ($) | Jul. 19, 2017 | Feb. 03, 2015 | Jul. 31, 2017 | Mar. 31, 2022 | Mar. 31, 2021 |
Amortization of Debt Discount (Premium) | | | | $ 10,000 | $ 19,000 |
Warrants Issued to MHW SPV II, LLC in Connection with Promissory Note, First Issuance [Member] | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 1,115,827 | | | | |
Class of Warrant or Right, Term (Year) | 5 years | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ 0.10 | | | | |
Warrants and Rights Outstanding | $ 167,000 | | | | |
Warrants and Rights Outstanding, Incremental Value | $ 6,000 | | | | |
Warrants Issued to MHW SPV II, LLC in Connection with Promissory Note, First Issuance, Tranche 1 [Member] | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 390,539 | | | | |
Warrants Issued to MHW SPV II, LLC in Connection with Promissory Note, First Issuance, Tranche 2 [Member] | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 390,539 | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ 0.20 | | | | |
Warrants Issued to MHW SPV II, LLC in Connection with Promissory Note, First Issuance, Tranche 3 [Member] | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 334,749 | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ 0.30 | | | | |
Warrants Issued to MHW SPV II, LLC in Connection with Promissory Note, Second Issuance [Member] | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 767,500 | | | | |
Class of Warrant or Right, Term (Year) | 5 years | | | | |
Warrants Issued to MHW SPV II, LLC in Connection with Promissory Note, Second Issuance, Tranche 1 [Member] | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 268,625 | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ 0.10 | | | | |
Warrants Issued to MHW SPV II, LLC in Connection with Promissory Note, Second Issuance, Tranche 2 [Member] | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 268,625 | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ 0.20 | | | | |
Warrants Issued to MHW SPV II, LLC in Connection with Promissory Note, Second Issuance, Tranche 3 [Member] | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 230,250 | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ 0.30 | | | | |
Notes Payable to Mr Berg and Mr Ikeda [Member] | | | | | |
Amortization of Debt Discount (Premium) | | | | 5,000 | 5,000 |
MHW SPV II, LLC [Member] | | | | | |
Debt Agreement, Maximum Borrowing Capacity | | $ 2,000,000 | $ 2,000,000 | | |
Proceeds from Issuance of Debt | $ 650,000 | | | | |
Debt Agreement, Maximum Borrowing Capacity During Post Amendment Period | | | $ 2,500,000 | | |
Debt Agreement, Post Amendment Period (Day) | | | 60 days | | |
MHW SPV II, LLC [Member] | Notes Payable, First Issuance [Member] | | | | | |
Proceeds from Issuance of Debt | | $ 945,000 | | | |
Debt Instrument, Term (Year) | | | 5 years | | |
Long-term Debt, Gross | | | $ 945,000 | 256,000 | |
Debt Instrument, Interest Rate, Stated Percentage | 12.00% | | | | |
Debt Instrument, Interest Rate, Stated Percentage, Paid in Cash | 6.00% | | | | |
Debt Instrument, Interest Rate, Stated Percentage, Paid in Kind | 6.00% | | | | |
Debt Instrument, Unamortized Discount, Total | $ 93,000 | | | | |
Interest Payable | | | | 173,000 | |
MHW SPV II, LLC [Member] | Notes Payable, Second Issuance [Member] | | | | | |
Warrants and Rights Outstanding | 115,000 | | | | |
Debt Instrument, Unamortized Discount, Total | $ 98,000 | | | | |
Amortization of Debt Discount (Premium) | | | | $ 5,000 | $ 5,000 |