First this came right during a post so I haven't had time to really analyze it but
I don't know if it was ever stated or not whether Hyuuga are born with their Byakugan already active. From what we've seen it would imply that they are but it's not been said. Bolt may be able to "unlock" Byakugan later.
Sharingan is activated by hatred/anger's reaction to chakra and loss of a close one. Maybe Gentle Fist(as in the name) is awoken by the chakra's reaction to some emotion like Love or Happiness.
I know what you might be thinking "but Hinata got it and no one loved her", to that I say; when she was an only child her father counted on her to be the heir so he gave her attention and care so she developed the feelings to spark Byakugan(in this theory) then her sister was born and she was looked over this caused her feelings of love and family connection to drop which is why she was so weak with her Byakugan in part 1. It was after part 1 when Neji helped train her that her feeling of love/family grew and she began to improve, then when she believed Naruto acknowledged her feelings it grew more. As I type more of this it grows from a thought to a plausibility, maybe gentle fist is the opposite of Sharingan since they came from the same lineage but different aspects.
I don't know if it was ever stated or not whether Hyuuga are born with their Byakugan already active. From what we've seen it would imply that they are but it's not been said. Bolt may be able to "unlock" Byakugan later.
Sharingan is activated by hatred/anger's reaction to chakra and loss of a close one. Maybe Gentle Fist(as in the name) is awoken by the chakra's reaction to some emotion like Love or Happiness.
I know what you might be thinking "but Hinata got it and no one loved her", to that I say; when she was an only child her father counted on her to be the heir so he gave her attention and care so she developed the feelings to spark Byakugan(in this theory) then her sister was born and she was looked over this caused her feelings of love and family connection to drop which is why she was so weak with her Byakugan in part 1. It was after part 1 when Neji helped train her that her feeling of love/family grew and she began to improve, then when she believed Naruto acknowledged her feelings it grew more. As I type more of this it grows from a thought to a plausibility, maybe gentle fist is the opposite of Sharingan since they came from the same lineage but different aspects.