When they're returning to mainland Japan, Kumano was hit by torpedoes from an American submarine and got damaged enough to be incapacitated to sail. Aoba sent a message in flashing lights to her... 6 November 1944

Kumano

How it sounds like for Kumano: Well, actually I really really wanted to tow Kumano back home to the mainland. But I'm also struggling here. So for the time being, I'll allow myself to run away from here

Following Aoba, a few days ago she had also been critically damaged by a submarine and after emergency repairs, in her current condition she could only muster up to 5kn. ...but that last line is really unnecessary...