Well, if the hints are complicated, then Nel is Celica's best friend. I personally don’t participate in the game and you don’t need to be friends with me there :-)
For several days, Celica must carry out the actions in the order in which Kimiko indicated (you can ask her again about this). And when Nel begins to interfere, Celica need to accept her help. It will be a good sign when Celica begins to doubt. But Celica must continue to meditate.