Due to overusing his sharingan while on a mission to save the Kazekage, Kakashi couldn't walk and had to be carried to Konoha’s hospital by Might guy, obviously.

After a brief examination by Lady Tsunade and you, she concluded that Kakashi needed bed rest and would stay there for at least a week.

And so, you became his medic-nin — helping him with whatever he needed help with.

“Could you please pass me my book?” He politely asked.