Indeed, the Software Choice is in Japanese (and is for Warp Server Advanced Japanese Edition).
The Warp 4 Chinese is the Simplified Chinese Edition (i.e. for the mainland Chinese market).
Fun fact, back when I had Passport Advantage in its final few years, it was supposedly for Warp 4 English. For some reason, IBM put copies of not only MCP1/2 English on my account, but also gave me Japanese, French, German, and Simplified Chinese. And, for some strange reason, ACP2 in German.