As with the Heart Events in Harvest Moon games, Events that offer an option for Partnership are critical to your success in 'matters of the heart' in Princess Debut. Here is the list of all Eligible Partners with the 1st and Last Opportunity for each to become your Partner in the game.
Eligible Princes in the 1st and all Subsequent Games
Prince Klaus
Klaus Rosencrans
Initial Level: 10
Age: 15
Sign: Gemini
Birthday: 20 June
Most Favourite: Cabbage Roll
Initial Technique: 75
Initial Artistry: 70
1st and only Opportunity for Partnership: Day 17
Klaus Rosencrans is the childhood sweetheart of the ‘real’ Princess. In order to obtain an opportunity to become his partner, you must set up the ‘Emerald Reunion’ Event on the 17th Day as follows:
On Day 3, when he asks about the magical powers of the Royal Tiara, choose: ‘You can fly!’
On Day 17, when he comes to your room, your response must be: ‘No, go on!’
When he asks what you told him long ago, the correct response is: ‘You look like a frog!’ If you respond incorrectly, however, you will have a chance to guess again until you choose the right response.
Note: There are NO other opportunities to become Klaus’ partner.
Prince Liam
Liam Goodrich
Initial Level: 5
Age: 17
Sign: Taurus
Birthday: 5 May
Most Favourite: Spaghetti
Initial Technique: 50
Initial Artistry: 50
1st Opportunity for Partnership: Day 6 before the Competition
Last Opportunity for Partnership: Day 29 at night at the Amusement Park
Prince Vince
Vince Wright
Initial Level: 3
Age: 13
Sign: Aries
Birthday: 28 March
Most Fav: Tuna Steak
Initial Technique: 40
Initial Artistry: 40
First Opportunity for Partnership: Day 4
Last Opportunity for Partnership: Day 28 at night before you go to sleep
Prince Cesar
Cesar Dubois
Initial Level 6
Age: 16
Sign: Libra
Birthday: 10 October
Most Favourite: Beef Stew
Initial Technique: 30
Initial Artistry: 80
1st Opportunity for Partnership: Day 6
Last Opportunity for Partnership: Day 27 if you refuse Vince's escort to the Concert
Prince Luciano
Luciano Barbosa
Initial Level: 11
Age: 15
Sign: Cancer
Birthday: 4 July
Most Favourite: Sushi
Initial Technique: 80
Initial Artistry: 70
1st Opportunity for Partnership: Day 6 AFTER the Competition
Last Opportunity for Partnership: Day 29 at night at the Amusement Park
Note that you MUST ask Luciano to be your Partner on the 19th Day at the Practice Hall if you wish to be able to be his Partner for the Ball. He will refuse but then will return on the 29th Day to ask you to be his Partner.
There is a way to become Luciano's partner before the Foundation Day Contest and still experience his return on the 29th but it is tricky. You must avoid ALL opportunities to become another Prince's partner and make certain that you do not dance with any one else while awaiting his return.
Prince Tony
Only opportunity for real partnership: 30th Day AFTER the Ball
Eligible Prince only in 2nd and subsequent games:
Prince Kiefer
Kiefer Bergmann
Initial Level: 8
Age: 14
Sign: Scorpio
Birthday: 17 November
Most Favourite: Fondue
Initial Technique: 65
Initial Artistry: 65
1st Opportunity for Partnership: in your 2nd Game on Day 20 in the Dance Hall
Last Opportunity for Partnership: in your 2nd Game on Day 27 if you meet him in the Dance Hall after refusing both Vince's and Cesar's invitations.
My Walkthrough for Princess Debut is available on IGN. Thanks to Alice for telling me about Cesar's offer on the 27th. I discovered a further opportunity for partnership with Kiefer because of it.