Apparantely end of Namek
Wait I just have to copypasta.
The first part is a Nnoitra flashback.
Kenpachi: Grab your sword now and take the woman back, your job is finished, from now on we will take care of them.
Ichigo: What are you saying! I have come all this way! I will …
Kenpachi: Who are you? You are a shinigami representative? Protecting your town is your job. Helping out that woman should satisfy you enough eh? If you understand, then go back now. And anyway you already had your fun, swinging that sword of yours around, haven’t you? Woman!! Heal my wounds!!