The antonyms for the phrase "are into one for" can vary depending on the context. However, some possible opposites of this expression may include "are not interested in," "are against," "are opposed to," or "dislike." These antonyms indicate a lack of enthusiasm, disagreement, or disapproval towards the given subject or activity. For instance, if someone says they are into one for hiking, the opposite would be that they are not interested in hiking. In short, antonyms for "are into one for" express a negative or indifferent stance concerning a specific interest, preference, or activity.