[To be fair, with Goku "friend" is generally a good bet. ]

... Yeah. [Goku thinks about it a little more, before shaking off his melancholy mood and smiling.] Yeah! You're right! Once we get back, we'll probably see him again! An' I can talk to him then!

[Surely once he gets the chance to just talk to Nataku, they can work things out. Even if they don't remember each other, they can still be friends. All the shinki here prove that. Just the thought cheers Goku up.]

Thanks, Hakkai!