Tsunade's Regenaration ability-a kekkai genkai

[Itachi Pein Uchiha]

I think that tsunade's regenaration ability is a kekkai genkai which she inherited from her grandmother that is uzumaki mito because she also had that symbol like tsunade in her forehead.I think tsunade awakened this ability after third shinobi world war.

 

[Dreckerplayer]

You can't be born with a seal on your body.

It has to be placed.

 

[Asami..]

No. It's a sealing jutsu used to store large chakra reserves. You can't be born with it.

 

[Orochimaruofthesound]

I say
Orochimaru gave her that seal

 

[Micho22]

First of all the yin seal is a diffrent jutsu and byakugou is a different jutsu
Tsunade just releases the yin seal and its huge chakra to use and activate byakugou