v3.26.3
N-2
6 Months Ended
Aug. 31, 2026
$ / shares
Cover [Abstract]  
Entity Central Index Key 0000859796
Amendment Flag false
Entity Inv Company Type N-2
Document Type N-CSRS
Entity Registrant Name JAPAN SMALLER CAPITALIZATION FUND, INC.
Document Period End Date Aug. 31, 2026
General Description of Registrant [Abstract]  
Share Price $ 12.63
NAV Per Share $ 14.37
Latest Premium (Discount) to NAV [Percent] 12.10%