I'm looking for a gender-neutral term for 'older sibling' in Japanese. They've got younger siblings who love them very much, and it doesn't work for the siblings to call them 'nii-san' or 'nee-san'. The closest I've found is 'Kyoudai', which is plural and/or not used for direct address from what I can tell. Is there anything I can use? Or should I just say screw it and have the siblings use some wort of hybrid thing like 'niinee-san'?
Japanese family words
Japanese sibling words
Japanese sibling terms
Japanese sibling terms unisex
gender neutral family words japanese
gender neutral japanese
Japanese sibling unisex
and also browsed a couple of language chatboards and wikipedia's entries on Japanese, which I can't remember off the top of my head.