Ani-ue is the respectful term for ‘older brother’ in japanese. The added ‘ue’ after the title for mother, father, brother, and sister were used before the Meiji era and are less common now, I think.

Me, and many other fanfic writers use ‘onii-sama’ to show a younger brother’s respect for the elder brother. I derived this from the commonly used ‘onii-chan’ and ‘onii-san’, figuring the same rule applied with the use of ‘-sama’. But I have now learned that aniue is the more correct term for very respectfully addressing one’s own elder brother, or speaking of someone else’s elder brother. The more I am learning japanese, the more I am realizing why this may be - ‘sama’ becomes oddly distancing to use for one’s own family members.

I hope this was informative to all inucest writers and anyone who wants to use these terms in their fanfics.

I am not a native Japanese speaker, so if there are any amongst those reading this, I’d really appreciate any feedback or comments on this and do correct me if I’m wrong.