Kisame wrote in his journal a lot. Posing as Tobi, he was able to spend a lot of time around the other Akatsuki members without anyone taking much notice of him. One of the things that this pseudo-invisibility had shown him was that in every spare moment he had, Kisame wrote in his journal.

Obito hadn 't so much as opened his own journal in years, not since the day he met Rin. He remembered hearing her gush about how her soulmate had drawn her pictures even before they could write and vowing never to open his own again. He hadn 't wanted anyone else 's words, only hers. Now, a lifetime later, he was still dedicating everything he had to a girl who hadn 't even loved him. Not that her lack of love in any way invalidated his own of course. Just because he knew they could never be together didn 't mean he couldn 't love her from afar. Right?