Yes, there are kanjis created in japan. For exemple, one of them, 畑（はたけ,farm）is original completely there

Yes. Chinese and Japanese character sets are the same most of the time, although small variations can be found in some characters between the two languages. Chinese characters were first introduced to Japan in the 5th century via Korea. (Hanzi) in Chinese and (Kanji) in Japanese are both written with the same set of characters (漢字) and have the same meaning "Chinese Characters". - There are Kanji characters which were created in Japan. For example, the Kanji 働 "to work", 込 "crowded" and many more were made in Japan. - During the twentieth century, various iterations of the Chinese government took the chance to simplify and standardize the Chinese character set (Hanzi). This new / standardized character set is known as Simplified Chinese and is easily distinguishable from Japanese Kanji where the differences apply. However, only a small proportion of (Hanzi) were ever simplified. Most have been left unchanged. Written Chinese is not alone in having undergone simplification. Japanese Kanji were also simplified by the Japanese government after the Second World War. This new character set is called (Shintaiji). It’s different again to simplified Chinese despite having a similar methodology: reduce the number of strokes in some characters and streamline components. - Example: 诚 (Chinese) vs 誠 (Japanese). This Hanzi / Kanji generally means “honesty” and “sincerity” in both languages.The version on the left is the simplified Chinese Hanzi, and the version on the right is used in both traditional Chinese and Japanese. The difference is in the radical on the left of the character, which means “speech”. It’s written 讠 in simplified Chinese and 言 in the other character sets.