Dating Charlie, Mel, and Ernst

Charlie
Go see him every Sunday and buy something from him the 1st time, but don't give it as a present to anyone. Take it back to him the next Sunday to trade it in for something else. Keep doing this until there's voice with his greeting, it happens at the 5th level of greeting (affinity is 135-170). You'll now be able to meet him on Saturday and invite him on a date.

Mel
Keep going to see him and getting love love flashes (any 2 people except you). Once Mel's greeting has voice, you'll be able to go see him on Sunday.

Ernst
Keep visiting him and making inspections. Once Ernst's greeting has voice, you'll be able to go see him on Sunday.