1) Forehead touch - Appropriate for: family, loved ones. Casual show of affection. 2) Beak touch (billing) - Appropriate for: partners. Romantic gesture suitable for public 3) Open billing - Appropriate for: partners. Sexual gesture inappropriate for public 4) Bird style - Appropriate for: no one/drunks. Don’t do this. Don’t be that tengu.
Any similarities between above models and existing tengu in the Karasu universe is definitely on purpose.