In August, Japan & Korea held 157 providers and was led by two payments companies, PAY.JP at 73.2 and PortOne at 66.3. Two months later the region holds 284 providers. PAY.JP is now 62.5, strong. PortOne is 47.1, developing. The region got bigger and its top got lower, and both facts deserve a reason.
Who leads now
| Provider | Kin Score | Band | Admitted by |
|---|---|---|---|
| LINE | 72.7 | exemplar | tag |
| SAKURA internet | 63.7 | strong | tag |
| PAY.JP | 62.5 | strong | tag |
| Actionpower | 57.0 | strong | hq, tag |
| 3-shake | 57.0 | strong | hq, tag |
| AB180 | 55.2 | strong | tag |
| JPX | 51.6 | developing | name, tag |
Scores are from each provider file, scored 2026-10-17. LINE is the only exemplar in the region, and its Agent Readiness is agent-native.
Why the payments leaders dropped
PAY.JP and PortOne each fell 8.3 points at the last scoring run, from 70.8 and 55.4. Soracom, the region’s connectivity anchor in August at 63.9, is now 51.5. All three were scored on rubric 0.24.0. Before reading that as the companies getting worse, check the rubric: a rubric release moves every score at once, and a drop of the same size on two unrelated payments companies looks more like a measurement change than a provider change. I cannot attribute the drop to PAY.JP or PortOne from the record alone, and I will not.
How the region grew
Membership comes from three signals: a regional tag, headquarters, or a name pattern. Of the 284 rows, 174 were admitted by tag alone, 74 by headquarters and tag, 20 by headquarters alone, and 16 involve a name match. The name patterns include Toyota, Honda, Nissan, Hyundai, Kia, Samsung and Sony, and they pull in the region’s best-known companies with its weakest records: Toyota 29.7, Nissan 9.1, Honda 8.9, Hyundai Mobis 5.2, Toyota Connected 3.9, Toyota Motor Corporation 2.8. The August post said the region was strong in automotive. By the record, the automakers are present, not published.
Across all 284, 156 are minimal and 68 emerging. Seven are strong and one is exemplar.
Tag-only admission also lets in providers that are not from the region. TheCarApi ranks fourth at 58.2, and its own description is a price surface across 39 European markets. That is our defect: a tag got it in, and the region page should not count it.
The region header claims 820 APIs. The provider files of its 284 members sum to 339. I cite the files.
Takeaway
The real Japan & Korea API market on apis.io is a short list: LINE, SAKURA internet, PAY.JP and a handful of Korean developer-tool companies. What would move it is the automakers publishing the connected-car contracts they already run, and on our side, tightening tag admission so a European listings API stops ranking fourth in Japan.
See the region at apis.io/regions/japan-korea/.