The Tomboy with a Girly Streak is much more common in Eastern media than straight-up Tomboys, which is a point of Values Dissonance with Western audiences; in Japan, gender roles are strict, and if a girl doesn't measure up to the Japanese ideal of femininity, then she won't be "desirable" enough. Thus, tomboyish characters in Japanese media are usually given enough feminine traits so that they won't be considered too tomboyish. Sometimes, these characters will have Tomboy Angst, either due to seeing their masculine traits as flaws, or because they don't want to be too tomboyish, and will sometimes object to other people calling them tomboys, because of their girly personalities and interests. Tomboy characters in Japan are sometimes Tsunderes due to their hidden girly sides, if they initially don't want to show them, particularly if they still have a tomboyish personality and want to keep their girly sides a secret from everyone else; however, if they have a girly personality, they are more likely to be more open about their girly sides, and in these cases, these characters are usually not Tsundere; nonetheless, Beware the Nice Ones.
In general Western societies, particularly the United States, gender roles tend to place greater emphasis on masculinity over femininity, which is why you're much more likely to see a pure tomboy in American media than in Japanese media. However, in European societies, particularly the United Kingdom, emphasis on masculinity is downplayed somewhat by the femininity standards of the English Rose archetype (the British counterpart to the Japanese Yamato Nadeshiko), so British women, and by extension other European women, are somewhat more feminine than American women; the same goes for Australian, New Zealander, and even Canadian women, all of whom take after traditional British femininity standards more closely than American women do, by virtue of being part of the British Commonwealth, which the United States is not a member of. Because of this, if there is a purely masculine tomboy in British or other European media, they will often be contrasted with a relatively more feminine tomboy who has a girly streak.
