Board Thread:Episode Discussions/@comment-25319479-20170531105724/@comment-734582-20170603223731

Lorenzo.r.1st wrote: oh.... ok. but shouldn't the chakra mode (something as simple as a chakra mode) not need seals, if it wasn't an actual jutsu? no other chakra related enhancement jutsus before this one shows that hand signs are needed. Ummmm. Rasengan doesn't need hand seals and it's a jutsu. We see Sarada use seals for her Sharingan. Dojutsu are still jutsu, hence "Dojutsu". With or without seals.

The Tenseigan is used to refer to two things, which is probably where the confusion comes from:

The Tenseigan is a dojutsu Hamura awoke.

The Tenseigan (energy vessel) is made when Hamura sealed his Tenseigan into some object that got powered with regular Byakugan.