HSP Visa (Academic): Are Book Chapters Accepted as Publications?

Hello everyone,

I’m planning to apply for the Highly Skilled Professional (HSP) visa under the academic track and have a question that I haven’t been able to get a clear answer to yet.

I already contacted the immigration office, but they couldn’t really clarify this point. I also tried searching Reddit and similar forums without success. I briefly spoke to an immigration lawyer as well, but the answer was fairly vague, probably because I haven’t hired them yet (which I may have to do if I can't get an answer here).

What I’m trying to figure out is the following:

Under the points system, you get points for having "3+ publications in indexed academic journals." I currently have 1 journal article and 2 book (chapter) publications, all of which are indexed in Scopus/Elsevier. The lawyer told me over the phone that indexing might be what matters, but said they would need to confirm after being hired. The immigration office also couldn’t give a definitive answer.

Since the official wording specifically refers to "academic journals" (学術雑誌), I assume that book chapters probably don't count, but I haven’t been able to confirm this anywhere.

Has anyone here dealt with a similar situation or can confirm whether indexed book chapters are accepted?

Thanks in advance for any help!