How do you unlock other characters in Robozou

Mother:
1st day: you have to use the vacuum cleaner 5 times before you can get the teacher. Keep entering/exiting the room where the vacuum is to max EXP, them use it. Time is of the essence: you have 2 ours in the period to control her and every enter/exit room gives 1 EXP and eats up 5 minutes of remaining time. You must finish this day with 90 or 100 EXP.
2nd day: Walk mother into your room and topless her (if you're bellow 100 EXP, enter/exit the room a few times). Now, control her back to the vacuum routine 2 times more. They walk her into exposition all the other times - keep the eye on the watch to make extra enter/exit exp points.
3rd day: topless walk and enter/exit all the 4 tunes. You should be around 350
points by now. (Save on this position: if the teacher doesn't appear on day 6, you'll loose all other girls - in this case, more vacuum, enter/exit and topless walk inside time frame.)
4th day: sleep use the top item not the second one. (There must be three choices!)
5th day: sleep use the top choice again

Sister and Teacher:
6th day: sleep again, but this time the teacher should appear and choose the top choice to control her. You have to wait after class until 16:45 to get control of the sister. If done right a cut scene will show you talking to her and an accident will happen to you sister.
This sequence MUST happen, or you will fail to see all other girls - see 3rd day.
8th day: keep your focus on the sister: raise her with enter/exit and shower. But during the time after class press talk, you will talk to the exchange student, keep trying until the teacher appears and then choose the top box to get 100 experience points each time.
9th day: continue with maxing out the sister and doing the talking routine during the after class time.
10th day: if you have the sister about 150 you can now go to the Shopping MALL with her for 50 points with the Enema item that pops up there. The Enema appeared always, for all characters, after this.
11th day: same as 10th
12th day: same as above

exchange student:
13th day: you should have the mother at 400 or above, teacher 400 or above and sister at 300-400 or more. You will have to do the same thing you did on the 6th day during the after class session-waiting until 16:45 and then going home. If done right you will have a cut scene of the exchange student talking to you, choose the top option again to control her.
15th day: work on maxing out points on everyone.
16th day: same as above.

Doctor:
17th day: This is it get tricky. You will have to use the exchange student and have her enter the Shopping MALL at exactly 16:35 that afternoon. You must enter the market from the school side and time it so that you pass under the banner at 16:35. If done right, walk straight ahead until the end of the walkway or hallway, turn right, walk 2 steps, turn left and you should enter the secret passage way to the doctor's office. You then will gain control of the 4th person.
18th day: work on getting the doctor's exp points up
19-21 day: same as above