Kakashi and many other ninjas that got captured by Hikari were kept inside an underground secret facility.
This underground secret facility was made in each city controlled by Hikari to keep with secrets of Hikari and also keep prisoners that Hikari does not want to reveal.
Their chakra signatures were sealed before moving them to the underground prison, also there are devices in the facility that stops the chakra signatures from leaking outside of the facility.
The ten elders transferred all the prisoners from underground facility to overground prison of Hotaru city.
This city was renamed to Hotaru after Hikari took the city and is now capital city of Hikari.
After some days, one of the elder of Hikari pretended to be hired ninja by konoha and secretly free all the prisoners and took them out of area controlled by Hikari.
(Inside The House of Minato and Kushina)
Shinichi is playing together with Naruto normally but it's just Ai controlling shinichi's body to pretended to act as a child, shinichi is inside his [Mind Space] lying down.
Ai: Shinichi sama, wake up, that fox want something.
Shinichi woke up inside his mind space and felt the Kyubi's chakra fluctuations, this was the signal decided by them if Kyubi want to talk to Shinichi.
Kushina (inside her mind): Kyubi what are you doing? what do you want?
Kyubi (inside her mind): Don't worry I am just stretching a little bit, I don't want anything.
Shinichi had tamed Kyubi and forced him to slowly open up and be friends with Kushina, now she and Kyubi talk normally.
Ai pulled kyubi inside the [Mind Space], kyubi is still a little fox and shinichi is 4 year old boy.
Shinichi: what do you want?
Kyubi: you both mother and son are same, asking same question, acting like I am annoying, I just want some fresh air and some space, this space is much bigger than the cramped seal space.
Shinichi: your actual chakra is still inside the sealed space, it's just your consciousness that is in this [Mind Space], if you want you can stay here but you will be forced back to sealed space once mum is some distance away from me.
Shinichi got out of his [Mind Space] leaving Kyubi inside.
Shinichi and Naruto were playing together,
Shinichi: Naruto, you know once we are 6 we will enter ninja academy.
Naruto: Really? I will become ninja too just like mother? but I don't want to become ninja, I want to become Hokage just like father.
Shinichi: you have to first become ninja first then you can become Hokage.
Naruto: Isn't that too much work, fine I will work hard.
there is knock on the door, earlier Shinichi got out of the mind space because he felt the anbu ninja coming toward the house
Naruto ran toward the door
Naruto: I will open the door, father is back early.
Shinichi also ran but stay just behind Naruto just to keep his brother's enthusiasm
Shinichi: I will open the door first.
Kushina also came from the kitchen, Naruto opened the door and outside there was an anbu ninja standing.
Anbu Ninja: Kushina sama, There is urgent meeting at Hokage's office, Hokage sama has called you too.
Naruto: mom, I will also come with you
Shinichi: me too, me too.
Kushina: It is an important matter, I will leave you at neighbour's house
Shinichi: mom, let us come with you, we promise to behave properly.
Kushina: No means no, you two just stay here.
Shinichi started rolling on the floor and started crying.
Anbu Ninja: Kushina sama, it's urgent meeting.
Kushina: Okay you both come with me but behave properly.
Shinichi stood up and wiped his tears
Kushina took them and jump on roofs to reach Hokage office Building, she let both Naruto and Shinichi in care of the people working there and went inside the Hokage's office.
Naruto: how do you cry with tears on demand?
Shinichi: I just have very weak mind, my tears come out too easily.
Naruto: don't worry I will protect you.
(Ai: using your skill [Actor] to cry with tears, ha ha ha (Ai laughed) )
(Shinichi: it's better to create a naughty spoiled child profile now so I can freely mess around the village in future)