Hiruzen: so let me revise the plan, Aizen here will enter Anbu where he will train and search for clues regarding the Senju disappearance matter, while me and Danzo here will be searching for any other clue that Aizen can't find.
Danzo: Is pretty good plan but there is something that I need to add, the Senju was a very big and powerful clan so they must have a lot of old enemies so we can start from there and see if someone has affiliations with these old enemies maybe they will let something slip.
Hiruzen: True, anything that you can find can be useful even some random clan that has some squabble with the Senju must be investigated, one of the founder's clans of Konoha is disappearing under our noses so we must know who is doing it.
Aizen: Yes, Hokage-sama.
Hiruzen: Now that this is dealt with, Aizen I will need some of your doc.u.ments for Anbu is just a simple general background check we do on each of our own, so while I know that's is impossible for a Senju to be a spy I still need to do it.
Aizen: Sure no problem.
Handing away my doc.u.ments to the Hokage we proceed to sign both necessary papers for my promotion and for me to be on the Anbu, finishing the paperwork the Hokage says tome me:
Hiruzen: Everything is in order now Aizen, I will give you 3 days of rest and after that come to this location *gives an address* where you will be introduced to the Anbu.
Aizen: Yes, Hokage-sama.
Exiting the tower I realized that is close to Mid-day, so why not have some lunch in a good restaurant, entering the Barbecue restaurant I chose a table and started to eat, the time passed and I finished eating my lunch, deciding to go back to the compound I immediately make my way there.
Reaching the compound, I go to the entrance of the library and make a Handsign [Taiju Mokuton Bunshin no Jutsu] creating 25 wooden clones, my objective, for now, is to read all the books accessible for me, expanding my knowledge in all areas for both Jutsu, elements and even History.
The clones immediately start to read each one of them a different subject, me the original I decided to train my body more while my clones go on a reading spree.
While I was training a red-haired woman who comes into my direction this woman, has a medium stature a pretty red hair, and a similar-looking seal to Tsunade on her forehead with my sensorial abilities I can sense extremely oppressive chakra emanating from her, noticing who she is I immediately greet her:
Aizen: Greetings Mito-sama, how have you been these days.
Mito: I am well Aizen thank you for asking, but I've come here to talk to you about something important, while I see that you are occupying yourself perhaps you can give some of your time to attend the request of this old woman.