In the initial plot of Naruto, there are two ninjas who use ghosts to seal ghosts, namely Sarutobi Hiruzen, a third-generation Naruto, and Namikaze Minato, a fourth-generation Naruto. Many people think that this technology was invented by three generations of Naruto, and then he passed it on to four generations of Naruto. In the end, Watergate used this technique for the first time against the Nine Lamas. In fact, according to Naruto's characteristics, the inventor of this technique is not three generations, nor four generations, but she has never been out of the mountain.
If you want to know the inventor of Ghost Seal, you need to know why you invented Ninja of Ghost Seal. Who is this ninja used against?
After the ghost is sealed, the performer and the performer will be sealed in the belly of a god of death, thus fighting endlessly. Then the so-called death is also a new kind of creature. They can't be summoned at will, and no one can pull the sealed person out of the belly of death at will, because summoning death requires a price, that is the performer's own life.
To put it simply, it is a trick of sacrificing oneself and then sealing the enemy into the belly of death, which is the so-called powerful sealing in different space. If this technology is used to deal with people, it may be a bit overqualified. It's really unreasonable for such a powerful ninja to deal with the enemy. Besides, a powerful person will never be caught by the arm. Even if you cast the ghost seal, it's hard to catch it.
In addition, according to the characteristics that Ghost Seal belongs to seal printing, the people who invented this technology should be the ninja of whirlpool clan, because they are best at developing seal printing, and the inventors of seal printing in Huo Ying are mostly whirlpool clan.
Since ghouls can't deal with very powerful people, what about some powerful creatures? The answer is, of course, yes. At first, this sealing technology was actually used to seal Kyubi no Youko. Although Kyubi no Youko is very powerful, it is only a creature, without much wisdom. After control, you can use it.
So how do we control bijuu? King Kong blockade is the best choice. This technology is the unique ability of the whirlpool family. It can easily suppress bijuu. After suppressing bijuu, the best way is to seal bijuu into a different space. After all, it is obviously a bit inappropriate to raise such a big creature.
Having said so much, you can actually judge it without too much speculation. The inventor of the Ghost Seal must be Uzumaki Mito, because she is the first pillar of Kyubi no Youko, and she invented all kinds of sealing techniques to suppress Kyubi no Youko and seal Kyubi no Youko. She is the leader of the whirlpool clan. After forming an alliance with Konoha Village, the Vortex clan became good friends of Konoha Village. The high-level officials of Konoha printed the logo of Vortex clan on their clothes, and then the Vortex clan also taught them endurance skills.
Since Uzumaki Mito is so powerful, why didn't Konoha come forward at a critical moment? The reason is that when Uzumaki Mito was alive, Konoha Village was quite safe. Her husband Senju Hashirama is still there, and no one dares to attack Konoha Village. After Senju Hashirama's death, his younger brother Senju Tobirama also managed the village well, so there was no need for Uzumaki Mito to take action.
Summary: The inventor of Ghost Seal is Uzumaki Mito. She taught this technology to Uzumaki Kushina, and then Uzumaki Kushina taught it to her husband Namikaze Minato. As for why three generations of Huo Ying Sarutobi Hiruzen also learned this technology, it is entirely because he is self-taught. When he was young, he was determined to learn all kinds of ninja skills, so he probably learned ghost sealing through scrolls left by the older generation of ninjas.