Boku (I think means servant somehow), so is very humble
I'm not fluent in Japanese, or a native speaker, but I'm pretty sure this is not correct. Generally, if you're trying to be humble, you get more polite, not less. "Boku" is less formal than "watashi". Taking your examples, if you look at Subaru and Seishirou's (and Aoki, too, I think) speech patterns, they both use fairly polite language ("desu/masu", "kudasai", honorifics like "san", etc.), but they're not overly so. If you want the more humble language, look at Hinoto, Hien and Souhi. Very ceremonial, very humble and respectful Japanese. Contrast both with Kamui and Fuuma (and probably Sorata, but Kansai-ben is not something I'm really familiar with), who both use "ore"/"omae" and the dictionary forms of all/most verbs ("Ore wa Kamui da", and all that).
"Boku" is a nice, middling-polite way for a guy to address himself without being overly formal.
(no subject)
I'm not fluent in Japanese, or a native speaker, but I'm pretty sure this is not correct. Generally, if you're trying to be humble, you get more polite, not less. "Boku" is less formal than "watashi". Taking your examples, if you look at Subaru and Seishirou's (and Aoki, too, I think) speech patterns, they both use fairly polite language ("desu/masu", "kudasai", honorifics like "san", etc.), but they're not overly so. If you want the more humble language, look at Hinoto, Hien and Souhi. Very ceremonial, very humble and respectful Japanese. Contrast both with Kamui and Fuuma (and probably Sorata, but Kansai-ben is not something I'm really familiar with), who both use "ore"/"omae" and the dictionary forms of all/most verbs ("Ore wa Kamui da", and all that).
"Boku" is a nice, middling-polite way for a guy to address himself without being overly formal.