From Hgames Wiki
all characters are at least 18
- The rank of your koikatu club can be risen from C to S by inviting more girls to club, talking with them and have sex with them.
- Higher ranks will reward you by unlock more H positions.
Story progress (物語進行度)
Complete the whole story with a heroine (witness the fin sign) will increase 25% of this meter.
- A H position in unlocked after finishing a story. Obviously there are 4 in total.
School search level (校内探索度)
- Each success increase 12.5% of the meter, and unlock 1 H-position.
- You can unlock 8 H-positions by this method.
Sex progress 性行為総合
Having sex with girls will unlock more positions. Each new position will increase 4.5% of this meter.
- Usually fuck a girl from her first time to be an "experienced" girl will be enough.