Currently level 120+ and I only have 168, I just recently leveled up however, my chakra stayed completely the same and not sure I'm ready for another few hours of straight grinding. I maxed out both Kaguya and Amaterasu, is it possible to get chakra from having more than 1 character above level 100? Does Kaguya even give chakra from leveling her? What other possible way is there to gain chakra without leveling up? Why does my Kaguya max out at Lv. 25 even though the standards are usually maxed out at 30?

Not that I know of, correct me if I'm wrong. If you're already at 168 on 120+, then leveling is the only way. Even then, it won't get any much higher than a few points after that.

As far as I know, Kaguya's level doesn't affect chakra points, and neither does multi character bonus. That one's for storage space, sushi carry limit, etc.

Currently only Amaterasu's level limit is 30, the others are capped at various other levels by CS, for reasons unknown.