Rather than a really small probability jackpot, I would like to see a scaling probability brought in.
I think if they gave .1% or .05% or even .02% chance-per-fight of getting the girl per shard, that would be cool, even if they had to reduce the shard rate a teeny bit.
In other words, when you have collected 10 shards, a 1 in 100 chance for the girl (or 1 in 200 if .05), per fight.
or at 50 shards, a 1 in 20 (or 1 in 40 if .05) chance for the girl per fight.
Once you get up to the high numbers, like 85 shards, you'll be getting her anytime.... that's a 1 in 11.75 chance to get her per fight.
This would allow them to keep both the feeling that we can really win at any time, get lucky sometimes, along with keeping the incentive system they clearly want for spending kobans and getting shards.