From Hgames Wiki
all characters are at least 18
Observations of the mini game so far:
- Three or more heads of one character starts building up the top meter in their color.
- Clearing either or both of the heads shown down to the left, over the circle, will slowly fill it up.
- The mini game seems to respond somewhat to which heads you use to fill the top meter. I.e. just lining up the main character with one specific girl will change the little meter down to the left to show the heads you are clearing. This happens once you've filled the top meter up a couple of times.
- Once the meter down to the left is filled up you can click it, unlocking a scene with the two characters it's currently showing. Since there are only H-scenes with the main character and the girls, you want to clear his head along with the girl you want to unlock scenes with.
- There are only four H scenes per girl, however some of them have additional dialog scenes after the last H scene is unlocked. If you get the same dialog twice or the meter down to the left shows different characters than the ones you're clearing heads of you've gotten all the scenes! Well done!
- H scenes in "story mode" differ from the ones in free mode. I will add more on that in the H-guide section.
- I am unsure if clearing equal amounts of heads for both characters matter (10 main character and 10 girl for example, to fill the top meter.) or if it's good enough to just clear three main character heads and then fill it up with the girl you want.