Q: the Chinese Characters in the logo とはどういう意味ですか?
A: the one in yellow means middle school?
Q: Characters とはどういう意味ですか?
A: personality


Q: "Characters" を使った例文を教えて下さい。
A: "I have many favorite TV characters." is a common one


Q: Characters are too small in this dictionary.
A: it sounds pretty good but it does sound like it’s coming from a foreigner. a better way to say this would be “This dictionary’s letters are too small”
Q: Characters go to the world of game, and fights using ourselves body. この表現は自然ですか?
A: Characters go to the game's world(?), and fight using their own bodies.
Q: Characters in this book are too small to read for a long time . I can't keep reading it more than 2 hours . この表現は自然ですか?
A: "Characters" is a really formal way to say it, and people will think you mean characters as in the people in the book.

"The text in this book is too small to read for a long time. I can't read it for more than 2 hours at a time." would be a natural way to say it.
Or "The print in this book is too small to read for long. I can't read it for longer than two hours at a time."