Amaterasu in japanese legends is viewed as being a female. So in the game, they made her image a female wolf. She doesn't stare at Rao's boob so much as her head is just in that directiong while it was Issun looking (and talking) about them. Besides, just because one girl stares at another girl's boobs, doesn't make her gay. :\
Good to know for the Japanese legend thing. I knew it was based off of such but have not read them. But, I just got through with that scene in the game (again) and I'd have to say she is totally starring at Rao's melons and with such intention! . And your right, but I'd say it depends on how long a girl would stare. Just because I busted in on a guy friend at a bad time (he was sleeping naked) and I saw something I didn't want to see doesn't make me gay. But I turned about real quickly and coughed to get him to get decent. LOL!
well you gotta check, check, and recheck your competition, and what better way than to stare at them for hours at a time? (but I'm a tad unsure how two different species could compete in chest size, especially against a god.)