Income taxes (Details Narrative) - HKD ($) $ in Millions	6 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Income tax rate	16.50%	16.50%
HONG KONG
Income tax rate	8.25%
Assessable profits	$ 2
HONG KONG \| Assessable Profits [Member]
Income tax rate	16.50%
CHINA
Income tax rate	25.00%

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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