Who is Kurama and how did story begin with Naruto Uzumaki?

Kurama or Kyuubi is a Bijuu in form of a fox with nine tails. Kurama was in Naruto body since infancy which was sealed by Minato.

The story begins when Kushina, who is Jinchuuriki of Kyuubi, gave birth to Naruto, at that time suddenly a masked ninja approached and tried to take Naruto who was still a baby to improve.

Minato was shocked and had two choices between saving Kushina or pursuing masked ninja.

Meanwhile, Kushina is struggling because she has just given birth, Minato has a choice between having to re-seal Kyuubi in his wife body or chase after masked ninja.

Minato finally pursued Masked Ninja with jutsu of time and space. But mysterious ninja managed to use a similar move, namely time and space.

With this move, a mysterious ninja thought to have come from Uchiha clan managed to bring Kushina to another place and then forcibly removed Bijuu from inside Kushina body using Sharingan.

Not long after, Minato came to save Kushina, and great thing was that Naruto mother still survived and didn’t die even though Bijuu had been removed from her body.

Minato then took Kushina to their baby place. Meanwhile, Mysterious Ninja managed to escape by bringing Kyuubi to Konoha and went berserk.

The village of Konoha at that time was in ruins and even caused many lives to die because of Kyuubi rage.

Minato then went to Konoha to use time and space moves to thwart Kyuubi attack, but a mysterious ninja arrived which made Minato have to face him first.

They took place in another place outside village of Konoha and won even though ninja managed to escape while threatening that an organization would one day attack Konoha.

Not having much time, Minato immediately returned to Konoha taking kyuubi to go far outside village with time and space jutsu.

Then Minato took his wife to kyuubi place to lock up kyuubi with chains.

Because Kushina has a jutsu that can remove chains from her body. So that it can lock up Kyuubi.

When he was dying, Kushina told Minato that she wanted herself so that Kyuubi could be sealed into her baby who was none other than Naruto.

But Minato refused what Kushina said, he just wanted half Kyuubi in Kushina and other half in Naruto.

Minato then decided to use demon seal of death to seal half of kyuubi into Kushina body. And other half sealed kyuubi on Naruto.

Minato gave opening seal to one of Kuchiyose frogs and kept what little chakra he and Kushina had.

It is same as they can meet their children, when their children are older.

Both of them died after Kyuubi sealing.

Then Hiruzen Sarutobi who was third Hokage took care of Naruto even though villagers didn’t give it because of Kurama in Naruto body.