More on this from yesterday.
I mentioned that there is the (I hope, scant) possibility for the U.S. District Court to decline the Title VII claim in the filing that I have been discussing. Even if the court did that, though, there is ability of the federal court to retain jurisdiction over the Japanese labor law claim, through a statute granting “supplemental jurisdiction” over claims that derive from similar facts and circumstances as the main federal claim.
Here is the relevant section of the law (28 U.S.C. section 1367):
(a) Except as provided in subsections (b) and (c) or as expressly provided otherwise by Federal statute, in any civil action of which the district courts have original jurisdiction, the district courts shall have supplemental jurisdiction over all other claims that are so related to claims in the action within such original jurisdiction that they form part of the same case or controversy under Article III of the United States Constitution. Such supplemental jurisdiction shall include claims that involve the joinder or intervention of additional parties.
. . .
(c) The district courts may decline to exercise supplemental jurisdiction over a claim under subsection (a) if—
(1) the claim raises a novel or complex issue of State law,
(2) the claim substantially predominates over the claim or claims over which the district court has original jurisdiction,
(3) the district court has dismissed all claims over which it has original jurisdiction, or
(4) in exceptional circumstances, there are other compelling reasons for declining jurisdiction.
So the U.S. District Court shall have jurisdiction over the supplemental claim, but may decline it under one of the four enumerated reasons.
The supplemental claim is a foreign law one (i.e. not a New York state one), and so it does easily fit into any of the listed four. Moreover, the statute of limitations has already run in Japan on a labor law claim, and the reason it ran was because the defendant took a long time in substantively responding to the EEOC. So equity would merit having the Japanese labor law claim staying in the U.S. District Court, (i.e. the defendant should not benefit from their own strategic delaying).