Whether you choose a male or female player character, following Aigis’ Social Link will cause her to fall in love with you.
In Persona 4, characters must face their inner demons (referred to as their Shadows) living inside of a mystical TV land and learn to accept themselves.
Their Shadow manifests itself as a doppelganger, and reveals the inner desire of the character.
Minako is somewhat less outwardly bisexual than Aigis, however she does still have a romance with Aigis and a heavily implied romance with Mitsuru.
These interactions are natural and considered positive.
He also makes some comments as to the beauty of men that further point to his bisexuality.