Did you perhaps read the raws? as far as i know there is no case of Aina losing her memories in Tempest of the Stellar War. In tempest of the battlefield, main girl Ma did lose her memories roughly 50-100 chapters ago. not sure when.
İ also just started but read in forum this. Seems like she lost her memories and regain back. Dont know other things..
wow, this guy must love using amnesia as a plot device, apparently he does it in every story he writes.
This is a spoiler regarding to raws i found in the forum. Dont open if you dont want. Spoiler: About memory Seems like princess lost her memories at vol 19-20. İ dont heard any other things.