to me, “Chinese characters” means a certain writing system that is used by several languages (and not just Japanese and Mandarin, but also Cantonese, Korean, Vietnamese etc.), but doesn’t inherently belong to any one of them. So, in my opinion, Japanese variants or 国字 are totally valid Chinese characters.
whether kana are also Chinese characters is a very interesting question. I think the main thing that makes them distinct is the purpose they serve, as they no longer convey any meaning by themselves but are instead used to write language phonetically. but I wouldn’t be so sure when it comes to 万葉がな. although manyogana was used the same way as modern kana it retained the shape of chinese characters. so maybe it’s the combination of both the evolved shape + different purpose that makes kana distinct from kanji?
to me, “Chinese characters” means a certain writing system that is used by several languages (and not just Japanese and Mandarin, but also Cantonese, Korean, Vietnamese etc.), but doesn’t inherently belong to any one of them. So, in my opinion, Japanese variants or 国字 are totally valid Chinese characters.
whether kana are also Chinese characters is a very interesting question. I think the main thing that makes them distinct is the purpose they serve, as they no longer convey any meaning by themselves but are instead used to write language phonetically. but I wouldn’t be so sure when it comes to 万葉がな. although manyogana was used the same way as modern kana it retained the shape of chinese characters. so maybe it’s the combination of both the evolved shape + different purpose that makes kana distinct from kanji?