Nintendo Co Ltd (NTDOY)
When looking at ADS’s (or other depository type interests/receipts such as ADR’s), the listing or trading of the actual ADS or ADR is irrelevant. All that matters is the qualifying status of the underlying shares. If the underlying shares are ISA qualifying (because they are listed on a recognised stock exchange or admitted to trading on a recognised stock exchange in the EEA, including the UK), then the ADR (or ADS) automatically qualify (regardless of its listing status).
The underlying shares for NTDOY is listed/traded on various HMRC recognised stock exchanges so the ADR is ISA qualifying.