SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash and cash equivalents (Details) - CNY (¥)	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Minimum
Cash and cash equivalents
Original maturities of term deposit	3 months
Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	¥ 872,102,927	¥ 533,697,058
PRC \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	852,651,899	505,445,775
PRC \| Denominated in EUR \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	18,233,516	5,986,595
PRC \| Denominated in RMB \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	334,796,621	278,917,866
PRC \| Denominated in GPB \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	504,471	244,790
PRC \| Denominated in USD \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	499,117,291	220,296,524
United States \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	691,290	10,087,973
United States \| Denominated in USD \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	691,290	10,087,973
Hong Kong SAR \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	11,556,322	14,709,796
Hong Kong SAR \| Denominated in HKD \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	79,213	78,206
Hong Kong SAR \| Denominated in USD \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	11,477,109	14,631,590
Others \| Cash and cash equivalents
Cash and cash equivalents
Total cash and cash equivalents balances held at financial institutions	¥ 7,203,416	¥ 3,453,514

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For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section 45
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=126970686&loc=d3e59706-112781

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.2)
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

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Period of time between issuance and maturity of customer deposits, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
-Paragraph D-E

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