This is a stressful achievement, be prepared to grind out and rage at some of the weird mechanics behind this game, it litereally can feel like playing rock paper scissors with someone who can read your mind...
There's some prep work that seemed to help greatly while chasing this acheivement, which is part of the grind towards 100% and another achievement anyways, so I would strongly advise working the following out first.
As Goro Majima, go to the Dragon and Tiger Sotenbori, you want to start doing Equipment Searches, to the Japanese Blacksmith Village, sending the Japanese Mercenary, giving him an additional 70,000,000Yen makes the timer 8 seconds, which is just enough time to get out of all the menus, then you can instantly turn it in to claim the rewards.
What you're grinding out specifically will be the following.
10 x Ruby
5 x Diamond
and a recipie for "Beads of Good Fortune"
Once you have all that, craft it, this will make it avaiable for Kiryu to purchase from the equivalent shop in Kamurocho.
Now, before starting the Cat Fighting, you want to equip Kiryu with some items that increase his finacial luck, I used the Beads of Good Fortune, the Secret Wallet and the Insulated Shirt.
With all that equipped, it really did seem to increase my fortune at this annoying minigame. Although you won't be successful 100%, it still seemed to be much better odds to me. So onto catfighting.
This will be similar to the other guide to this achievement, where as Jennifer is the go-to gal for betting on, and although I'm not sure it had any effect, betting the maximum every time just to be safe. Also read the ticker, more often than not it will read a negative statement for Jennifer, if that's the case, back out and go again. You want something positive, humming her own theme, students grades increasing, or had a choice steak were the stand out ones for me. Once you see one of those, then proceed to make you bet ad get cracking.
The game itself is psuedo, rock-paper-scissors, except that it's more the AI needs to decide it's going to let you win, there is no rhyme or pattern here, it does what it does, so I found hedging bets to be the better course. I would pick whatever would lose to the opponents weakest hit, and beat their strongest, and this worked fairly well. So the following move set was what worked for me.
Oppenent - Move
Rei (Ninja) - Rock
Sayuri (Nurse) - Paper
Franchesca (Vixen) - Scissors
Maria (Cop) - Scissors
Yurie (Student) - Scissors
Momoko (Hostess) - Scissors
Yuiko (Diva) - Rock
And just hope, there will be occasional rounds where the AI decides it's going to win and no matter what you pick, it will ALWAYS trump you, so be prepared for it to be a little unfair, also keep an eye on what colour the faceoff screen goes, if you see Rainbow colours, be prepared to spam the B button, this can sometimes win a round in a single move. If you don't see rainbow colours, feel free to skip the move to save some time.
If you draw, and you will alot, there is a button bash faceoff, althouth this feels like it's really stacked in the AI's favour, i found letting the AI make 1 spot of ground before I started bashing the button helped some, but there will be plenty of times where no matter how fast you hit B, the AI WILL win no matter what. Just keep going and with a little luck, the odd loss won't matter too much.
Finally, don't throw your controller at the screen when you think you've won, only for an opponent with the 'Comeback' perk to get up as Jennifer is celebrating on full health, only to have her arm broken and instantly lose, it's rare, but oh-so frustrating.
Be patient, and do a few at a time, don't solely pour your efforts into grind these 10 wins back to back. it will feel easier to space out over a few days, there's alot of other stuff to grind out to fill the gaps.
Good luck everyone, I hope this helps some :)