Regarding Self-Training Yielding Higher Ranks Than Direct Training...

I usually train on the deserted island or with ramen, but for some reason, ramen during self-training seems to yield the best results. I especially want to train么Satono Diamond,么Kare-chan, and么Vibes to a high rank, but is it difficult for me...😔 When I train them, I only reach around UD for max speed, let alone LG.