Episodes/arcs/characters that focus on the theme of finding family?

For a long time I've been thinking about writing an essay about the theme of found family in Gintama. Part of why I've been procrastinating for so long is I'm unsure of where to begin. It's such a long series and I was wondering if this community could help me compile a list of any particular episodes I could rewatch that focus on this theme?

The most prevelant characters I can think of that contribute to this theme the most are Gintoki and Otose. I looked at my notes and I just wrote down "Yorozuya, Shinsengumi, Nobume, Takasugi". Thinking about it now maybe I just need to rewatch the whole series 😄. But if anyone could help me narrow down places to find this, I'd really appreciate it. If the manga has anything relevant that the anime cut out I'd love to hear about that too!

Regardless of my request, I thought it would be fun to just start the discussion around this theme.