Hasegawa, Otae and Katsura on Taking Care of Shinpachi and Kagura
L78 "And you guys are snooping on him? Are you nuts? Let's get out of here! Come home with me! I'll buy you pickled seaweed and-" (Hasegawa)
L92 "Please stop doing such reckless things. If something happened to you, Shin-chan and Kagura-chan would be sad." (Otae)
L94 "Wait, if anything happens to you two, I... won't be able to face Gintoki." (Katsura)
L229 "That's good enough. In order for them to become stronger they must seek their own path.. Yeah they've got to exceed their own expectations first. It's because they know their own strengths after all. For now we'll just stay back always watching over them. That's right for we are your instructors fo whatever life should throw at you." (Katsura, Gintoki, Otae, Hasegawa)
L294 Santa Arc. Hasegawa gets invited by Otae and Shipachi to have a party at the dojo. Katsura wanted to show up as Santa but he couldn't have the proper timing.
L379 "Stand up the two of you... Let's all go back together to where our leader is." (Otae)
L575 Sakamoto: Gintoki fer the sake of the new friends ya found that’ll be supporting this country. Use these old friends a’ yours.
Zura: It is the duty of old friends to oppose an old country. You have to connect to your new friends to the new country. Gintoki, us old friends will be okay. Go fight for the things you really want to protect.
Takasugi: You’re going to leave a country in the hands of powerless kids like that? Is every last one of you out of your mind? Kid, I didn’t save your life for something like that. Do not hand Gintoki’s head over to anyone else. Next time, things like countries will not matter. I’ll clear everything and go to take his head. I’m going to settle it.
Sakamoto/Katsura/Takasugi: So until then Gintoki is, our friend, is in your hands.
Shinpachi: Okay!
L704
Otae: "Shin-schan, if you're going to become Yorozuya that can grant Gin-san's wish then we will grant you wish and become a Yorozuya."
Hasegawa: If it's to the final boss, I can get ya there on the cheap.
Katsura: Gintoki, they're up ahead. Most likely that man and the rest of the Yorozuya are up ahead from where you are. So if there's anything you have left undone, you'd better hurry up with it.
Otae, Katsura and Hasegawa caring for the Yorozuya, caring especially for Shinpachi and Kagura from beginning until the end.
The three, out of all adults in this series, are the ones who act like their guardians/mentors when Gintoki is away (or out of commission). They're the ones closest to Gintoki and understand that Shinpachi and Kagura's well being, safety and happiness are important to Gintoki (and vise versa). The other Joui join in sometimes ofc, but I find the concern from these three the most striking and clear.
The Gintoki / Otae / Katsura / Hasegawa friendship unit is one of the most underrated friendships in Gintama imho. They hang out together in peace times and performed different and important roles in war times. The other three adults aside from Gintoki take it upon themselves to watch over Shinpachi and Kagura. They're all good buddies to each other too.
