For Memetchi: You need a Young Mimitchi or Oniontchi. Then, just be a little forgetful of both body and heart needs. Hopefully you get Memetchi.
For Hanatchi: You need an Ichigotchi or Hinotamatchi. Then, be diligent about the heart (happy) needs, but more forgetful (not too forgetful!) with the hunger needs.
Does that help at all? :furawatchi: