The bulk update request #13064 is pending approval.
change category aika_(disambiguation) (0) -> invalid
create alias aika (0) -> aika_(disambiguation) (0)
create alias aika_(artist) (0) -> aika_(disambiguation) (0)
create alias aika_(character) (0) -> aika_(disambiguation) (0)
Reason: There is no clear singular dominant "Aika", and there are a few tags which simply assign a non-specific "Aika".
I have properly recategorized all ambiguous Aika tags already.
EDIT: The disambiguation page itself is now set up as well.
Updated