Board Thread:Theories and Speculation/@comment-1930928-20200816130234/@comment-1930928-20200817012039

Yes normally I would agree with you, that the tenketsu can just be reopened once closed. However the gentle fist injects chakra into the chakra pathway system which can not only shut tenketsu, but also damage the surrounding organs. There aren't many who can operate normally after being hit with the gentle fist. As you noticed, closing off tenketsu adjacent to the eight gates could also be an option for shutting down the technique.

As a side bar, am I the only one who doesn't understand why Neji couldn't master the eight gates? I mean after all the chakra pathway system and tenketsu are a Hyūga's bread and butter.