shouldn't it be the opposite? since Kaban became a regular human then she is the one who will age and die while the other friends will continue to exist, baring accidents and ceruleans.or am i misunderstanding something about the lore?
The history between pre-Gura and shark themed characters is well known but I would not be surprised if someone (either herself or a Hololive staff) also took inspiration from Shuuji's Shark Girl manga before making the character concept. The fact that there's 'Gura' on both sides is too much to be coincidence.