- Estimated achievement difficulty: 2/10
- Offline: 46 
- Online: 0
- Approximate time: 150+ Hours [With exploits] 300+ Hours [Without exploits]
- Minimum number of playthroughs needed: 100+ Vacations
- Missable achievements: No
- Does difficulty affect Achievements: No
- Unobtainable/glitched Achievements: No
- Extra equipment needed: No
Welcome to Dead Or Alive Xtreme 2! Due to this game's open approach to how you play this game, this roadmap will be one of the most optimal routes in order to complete this title as fast as possible. Regardless, there are several alternative choices you can make depending on how you feel you wish to complete this challenging game.
Before digging into the process, it's important to familiarize yourself with some useful tools to help make the achievements easier. First things first is a comprehensive checklist that will help you keep track of everything required to obtain all of the achievements in the game. You can find several useful resources here like each girl's favorite items, colors, and hotels.
Link to Checklist
Second is to understand the very important 'sign out glitch'. If you aren't fond of using exploits or glitches in order to complete a game, this video, and this game are probably not for you.
Sign Out Glitch
This glitch is applied not only to the roulette table, but to gifting as well. When you're about to click the final yes when gifting an item to someone, hit the guide button and load up the sign out screen. If the girl declines an item, notified by the unique sound or the image of the gift being opened on the bottom right, you can sign out. If you see the girl change into the swimsuit, hit the guide and continue on.
Step 1: Money Making
Initially, we need to work our way up to the approximately 4.6 million Zack Dollars needed to successfully exploit the roulette tables. To begin, start a vacation with each and every girl and win enough Zack Dollars through volleyball or jet ski races in order to make around 4.6 million. I recommend volleyball as you need 50 wins per girl in order to unlock the "Strange Volleyball" which is required for the final achievement.
Once you have 4.6million Zack Dollars, you can successfully exploit the roulette glitch. Unlike the video, I recommend max betting on the first third of the table, rather than loosely betting on the first half. The profits tend to outweigh the lowered odds of winning in the long run. It is here that you will want to make enough to purchase the girl's swimsuit set to unlock the initial 'X Collection' achievements. After you've done this, fall back to this method whenever you need more money to buy sets for other girls in order to gift.
Note: If you are not abusing the sign out exploit, Jet Ski races tend to be one of the most efficient ways to make money after the patch.
Step 2: Early Gifting
To start off, pick who you will gift to and who you want to gift as. Once you've done this, buy the complete collection as well as a few of the giftee's 'love' items (detailed on the 'DOAX2 TRACKER' tab on the checklist under each girl's name) and make sure they are wrapped in the giftee's favorite color.
After you're ready to gift a complete collection, begin a new vacation and start off by gifting a love item to your giftee as soon as you can find them. I prefer to use the sign out glitch here because some girls will actually reject the love item and it only wastes time. Ideally, we want the girl to have a couple of hearts when you see her by the end of the first day. After that is done, gift her a love item at night in your room.
Step 3: Gifting
Here's where things get a little less strict. Depending on who you're gifting to, you need to approach things differently. For instance; Tina, Ayane, and Helena all hate to be bothered in the morning. When I'm gifting to these girls, I use the morning sessions as a time to restock on love items if I'm running low and I avoid gifting to them. Christie only likes to be visited once a day so, sort of like the anti-morning girls, visit her once and then restock on love items, win some volleyball matches, etc.
In general, on an even numbered day, gift the girls cheaper/easily accepted gifts. Typically the more expensive the swimsuit, the less likely they'll accept it. However that is not always the case. On even nights, there's rarely a need to gift a love item as their hearts should still stay at max. (Note: Kasumi is the only exception as her heart gauge depletes quickly and she should be given a love item AT LEAST every night). On odd days, try and gift some of the more expensive suits, which also happen to deplete the heart gauges faster. Once it reaches night time, gift a love item. Repeat this process, starting new vacations if necessary, until you've gifted the complete set.
After a girl has received an even number of complete collections, you can play a day as that girl to receive your achievement after completing Day 1. If you want to obtain achievements online, install the patch before selecting the girl, play a day and get the achievement, uninstall the patch, continue to use the sign out glitch.
This step is the most lengthy part of the process. Switch back to Step 1 when you need to obtain more money and make sure to never fall under 4.6 million to properly abuse the roulette glitch.
Step 4: Mop Up
Once you've gifted complete collections to every single girl and received 900/1000, you just need all of the items left for each girl. If you've been casually storing items as you've received them from playing, the items tab should be nearly full with each girl. Just buy every item on the checklist that you still haven't obtained, such as the various volleyballs, nail polish colors, game tickets, etc. Buy all of the accessories as well to finish most of the collections.
The last few unique items are the Strange Volleyball and the Secret Ticket. 50 volleyball wins will net you the Strange Volleyball. For the Secret Ticket, you must get a jackpot on Christie's slot machine 9 times (doesn't have to be done consecutively). It's best to have over 15 million and hold A at the slot machine. You should balance out wins and losses to stay relatively even. After you win the jackpot 9 times and see the whole 'Private Dance' cut scene, you will be given the Secret Ticket from Zack the next night.
Fortunately Jet Ski's are NOT required. Do not worry about purchasing these. Everything else is however, so make sure you have at least one of each item stored in your collection. After obtaining every item with every girl, you have officially completed one of the most challenging 1k's out there!
Hopefully you will benefit from following this basic outline of how to successfully gift to each girl. After going through two save files of gifting, this method has been fine tuned to find a solid balance of efficiency with risk. Fortunately, with the sign out glitch, risk is almost non existent but rather purely relies on patience. I hope you enjoy and happy achievement collecting!
[XBA would like to thank IceKingz for this roadmap]