As a fan of online novels, I can't judge the novel as plagiarized. However, based on my knowledge of online novels, there are indeed some similarities between Charlie IX and the Little Tigers. These two works both contained elements of exploration, adventure, magic, and so on. The protagonists also experienced many difficulties and challenges. In addition, their protagonists had some mysterious items and skills that could help them solve their problems. Some of these similarities might be deliberate plagiarism, but more likely, the author was influenced by other works or inspired by his love for the two types of novels. Therefore, I suggest that you have a deep understanding of the work and read it to make your own judgment.