Board Thread:Theories and Speculation/@comment-26704954-20150821182356/@comment-24776570-20150821210330

Well, I don't know about sealing a physical person inside of another person, but you sure can seal people. Physical objects can be sealed as seen with the lighting blade flash creation. So, it makes sense that a person can be sealed away as well. Uzuamki sealing technique would be a good example of something with that potential.

Now, the question was; "Can they be sealed like a tailed beast." In my opinion, no they cannot; not in the same way at least.

Though as a few have pointed out, you can seal fragments of their chakra within yourself as seen with Minato and Kushina. You could even look to Obito 'taking over' Kakashi albeit I don't think that was a seal.

My answer is that while it would not be the exact same process, and with a different outcome, you can in fact seal people into other people.