Sorry for my bad english. I found that Installing other-model system-titles is possible on 3dbrew. (https://www.3dbrew.org/wiki/Titles#Installing_other-model_system-titles) I think it means system titles of O3DS can be installed on N3DS and it can be a only way to downgrade Korean N3DS to arm9 exploit working version. (Initial version of KOR N3DS is 9.6) Does anyone has any idea how to do this? P.S. neobrain, can you help me?