Without China's cultural traits, your own culture will look that of the cave men.
Without the Chinese characters, you won't even have your own vocabularies.
I'm not saying that the Chinese did not influence Japan, because nothing could be further from the truth. Yes, Japan , particularly the early period, was influenced by Chinese buddhist missionaries, bringing to Japan the Buddhist faith. But before this, Japan had already a vibrant Shinto religion, which was not supplanted by Buddhism, but merely incorporated the Buddhist principles. That is the unique trait of Japanese culture and civilization. We incorporate new theories, new philosophies and apply it to the Japanese context.
China had a role in introducing the Confucian culture to Japan, but this culture then developed its own uniquely Japanese traits. As for the writing system, Japanese writing incorporates a dualist system. We use Kanji (Hanzi), but we also incorporate our own uniquely Japanese character system -- Hiragana and Katakana. You see, Kanji is incorporated into the overall system.
I don't care that the Korean ultranationalists' opinions.
The fact has showed that they are an uncreative nation without the capability to create their own original culture.
The Koreans are vehemently proud and a martial race of people. They resemble us Japanese in many ways; or one could say that Japanese resemble them...in many ways. lol.
As for your claims of Koreans not producing their own culture , that is absurd. They have their own unique culture. Remember they do not even use Chinese characters (Hanja), but use a phonetic writing system known as Hangul. Which is very similar to Japanese Katakana and Hiragana , which also is based on a phonetic system.