Title says HAPPY LUCKY whatever (I hate when I can't even decipher something that should be written in English). The guys have the kanji for the days of the week (or for the elements Patchouli uses :P) for heads.
Other than this, I'm as lost as you. There's a lot of saliva.
The kanji are indeed the ones used for the days of the week, and the reason they're used by Patchouli in that way is that the days are named after elements, like gold, wood and earth. For some reason, the people with those kanji for heads are all from shounen anime.
I thought the logic behind it might be that she's looking forward to watching them after school, and the kanji relates to what day they're on. Unfortunately for that theory, the days they have for heads aren't the days the shows are on...
