野性 (yasei) means "wildness" or "primal instinct," referring to the untamed energy and natural courage within a person. It is more evocative than simply saying "wild," carrying a sense of an instinctive, powerful side of oneself.
In the song, the singer urges listeners to awaken the 野性 sleeping deep in their hearts, break free from their chains, and live boldly instead of conforming. Its striking imagery makes it one of the song's most memorable and motivating words.
"WILD FANG" is Janne Da Arc yelling at you to stop being polite. The chorus opens with "研ぎ澄まされた爪を立て" (raise your sharpened claws) and "今輝くために その牙を剥け" (bare those fangs so you can shine now), and the whole song treats your hidden 野性 (wild nature) as something everyone carries: "誰も皆 胸の奥に 眠る'野性'を宿してる" (everyone holds a sleeping wildness deep in their chest). The verses go after fake smiles and going along with the crowd. "右にならえ" is the classroom command "right, dress!" used when lining up, so "右にならえそれでいいの?" (just copy the person on your right, is that really fine?) is a jab at conformity, followed by "それじゃただの機械じゃない?" (doesn't that make you just a machine?).
The second half gets blunter, and honestly a bit much in the best way. "できるできないじゃなくて やるかどうかただそれだけ" (it's not about can or can't, only whether you do it) is pure pep talk, and then the singer tells you to "月に吠えろ!" (howl at the moon!) and "野蛮に踊れ" (dance like a savage). He has no patience for anyone scared of pain: "甘えているガキはお家へ帰れ" (spoiled brats can go home), where ガキ is rough slang for a kid and 甘える means leaning on others like a pampered child. Watch for 我無者羅, an unusual kanji spelling of がむしゃら (recklessly, with everything you've got). The odd comfort line keeps coming back too: "試練は乗り越えられない人に 襲いかかりはしない" (trials don't attack people who can't overcome them).