For now Tsunade is availabe only through the Sakura's Lovers' Route. This is how you can activate Tsunade, (points 1-5 can be done in any order):
We ran with Tsunade when we left the house, talked to her, and arranged dinner at Ichiraku.
We go to Ichiraku and ask Ayama to prepare a special ramen for Tsunade.
We go to the hospital and watch one scene as Tsunade changes her clothes.
We are waiting for the evening and we go to Ichiraku Ramen, but Tsunade is not there. Let's go find her in the village. You don't have to go very far, at the entrance to the village we see a beaten guard who tells us that Tsunade drank and hit him. Also, Tenten walks with her.
We return back to Ichiraku, there drunken Tenten and Tsunade are waiting for us there. We feed them with ramen, then we go with them to the restaurant.
In the restaurant you will have a choice of who to pay attention: Tenten or Tsunade. If you choose Tenten, there will be a scene with a footjob under Tenten's table. If is Tsunade, there will be a scene with a handjob under Tsunade's table.
After the restaurant, we will see Tsunade to the Hokage residence.
> Continued in future versions.