Extra mode is unlocked after finishing the game once.
Lists all childen produced at the end of each run.
All of Havel's children in the Arena currently selected under Status will battle each other, and the output displayed. This has no other gameplay effect, but can show relative strength (and luck) of children produced by each completion. This also shows the abilities the children use in Raiding, including special attacks, support from mercenary squads and your highest scoring Harem girl.
The Harem board is the same 13 by 7 -3 tiles as the Lake. The object here is pure speed; collect as many matches as quickly as possible for points before the time runs out. As the girl's pleasure counter adds up to orgasm and your charge counter adds up to ejaculation, you earn more points. Ejaculating enough within a time limit will also give you a pregnancy bonus to score, and improve that girl's combat support in the Arena.
There is no penalty at all for quitting a board early (English version only; in later Japanese patches Vitality is lost when quitting,) or ending with no matches to complete it. A good layout for fastest completion is completely random, so if you find you're taking too much time casting about for the next match, you may spend your remaining time better by quitting and retrying for an easier board. However, the only way to get the pregnancy bonuses is to clear the board within 3 minutes for Marielle, 2 minutes for Yeadow, and 1:30 for Semirama. (In the Japanese patch, Heine from Way and Serica, a preview character from Way 2, can also be obtained.)
Many of Havel's stats have an affect here. Your overall time limit is based on your Vitality, the length of the Pleasure meter is based on Penis, and the length of the Charge meter is based on Penis Skin. So with more Vitality you'll naturally have more time to attempt and finish more boards, with lower Penis Skin you'll get more Ejaculations in that time, and with higher Penis you'll score more Orgasms. It's possible to get the Pleasure and Charge meters down to two bars, so that every other match you make scores Orgasm points. The real Breeder's Cup challenge is to impregnate all girls in a single night.
The potential for scoring high and impregnating improves with each game played. Each girl has training and technique scores that begin at 0% are raised through matches. Training is the chance that a tile match will increase the girl's Pleasure bar, and it raises each time the Pleasure bar fills up to Orgasm. Technique is the chance that a tile match will increase the Charge bar, and is raised every time the Charge bar fills up to Ejaculation. How much the scores raise depend on the Havel's Penis and Penis Skin scores and that individual girl's disposition; ie: Marielle is more warmly disposed to the character, Yeadow is anally inclined but resistant to vaginal penetration, and Semirama is completely hostile.