I was making sure I followed Goryus' guide exactly so that I'd be sure to recruit all the secret characters, and somehow I already managed to miss these two. I did take the southern route from Yuimen to Helmet Peak, then headed back towards Yuimen and took the northern route all the way over to Kucha. As soon as I saw the cutscene in Kucha, I headed over to Plateau Mountain and Lotus Cave without taking any detours and headed straight back to Kucha immediately after rescuing the girls. The cutscene here only went as far as returning the girls to their home and the party decided to be on their way. I do however, have several saves just because I felt like this sorta thing would happen to me, but I'm not sure how far back I need to rewind in order to correct my apparent wrongdoing. I will say that I did not trigger the Reikan event at the post in Kucha prior to rescuing the girls, but I have no idea if that has any bearing on this mess. If anyone has any clear-cut method to recruiting Kinrei and Ginrei, I'd appreciate it very much.
Can't offer too much other than the following:
1st time I played this game a million years ago, I got them both, so I didn't know they were missable until this thread.
On the current replay, I was loosely following SYusup's FAQ, and I know that I cleared the north & south paths before advancing to Mt. Cloud & Kucha.
1st, I went north to Lucky Temple & Firetop, then back down to Turfan, Mist Mountain, Biku, Helmet Peak, then back up to Infidel City, then finally advance on Mt. Cloud, Kucha, down to get the girls, and when I brought them back they joined.
Oh, I also triggered the special fight VS Reikan, but I missed Reikan completely on my 1st playthrough (told him Ryorin was my gf), and I still got the girls, so I don't think they are related.
Anyways don't know if this helps, but that's my two cents.
I missed them too from following the FAQ... I think you're supposed to do everything before Mt. Cloud.. Then go to Kucha and get them and then go get Reikan.. I'm not sure why.. It seems pretty stupid that if you do the battle with him before them they just decide not to come with you.
Because I did the Reikan battle already and now I don't have them. But I dunno :/