Akagi obtained her second remodels on the May 21st 2019 (Spring 2019 Event) update, termed Kai Ni and Kai Ni E and shows (along with the Ise-classes' own remodels) how Shibafu has improved.
She keeps the same basic outfit with a few new details and changes, her skirt is now unambiguously a shorterned hakama, her sleeves gained ribbon trimming while her thighhighs have been turned into tabi with black thighhigh gaiters. Her gear is built up from base with, at Kai Ni, two extra quivers on each sides of her hip, a black flight deck, a black yumi and more modern AA guns (long 10cm guns). For Kai Ni E, she is dimly lit for night operations, reflecting her new ability to fight in night battles. Her eyes gain a slight glow (although this can be attributed to how the iris interacts with light) and she also replaces her AA gun and her left quiver for a sword.
These remodels are essentially hypothetical organic remodels of sorts, reflecting what she could have been if she didn't sink at Midway. Indeed, there were plans to modernize Akagi after Midway that would have remedied aiming and firing radius problems with her 120 mm twin mounts by moving them one deck up for cross-deck fire, and ultimately replacing these 120 mm with newer 127 mm dual purpose twin mounts.
This tag implicates akagi_(kancolle) (learn more).