Based on pixiv tags this is Amagi-class battlecruiser Amagi as an Akagi-class aircraft carrier. Well, at least that old tag for fanmade KC battlecruiser Amagis got something new (well, not really new given that this was originally posted on pixiv in 2015) under it.
I kind of doubt that they would have used a kanji character on her flight deck when the rest of the Kido Butai used katakana, but that does raise the question of how they would have differentiated her from Akagi, since they both start with 'ア'.
