Here's a collection of save files, you can use them to get some achievements incase they never popped for you, you played the game on another console or there's a particular part of the game you wanna skip. I've made guides like this for all the other Yakuza, Like A Dragon and Judgment games. Links to all of them can be found here and on my profile.
https://gtm.you1.cn/sharedfiles/filedetails/?id=2689025548
https://gtm.you1.cn/sharedfiles/filedetails/?id=2585769811
https://gtm.you1.cn/sharedfiles/filedetails/?id=2586740791
https://gtm.you1.cn/sharedfiles/filedetails/?id=2379715518
https://gtm.you1.cn/sharedfiles/filedetails/?id=2389968624
https://gtm.you1.cn/sharedfiles/filedetails/?id=2408950501
https://gtm.you1.cn/sharedfiles/filedetails/?id=2440359743
https://gtm.you1.cn/sharedfiles/filedetails/?id=2447367563
https://gtm.you1.cn/sharedfiles/filedetails/?id=2864943075
https://gtm.you1.cn/sharedfiles/filedetails/?id=2872921349

Listed below are saves including some for achievements, a finished game save file in Premium Adventure and more to come!
If you own the DLC you can also use the premium adventure save to play the Big Swell or do New Game Plus

I will spoiler any important names but gameplay/location spoilers may still be below.
A lot of these achievements are ones you will get naturally, but just in case something glitched out for you or you did them on a different platform or you wish to skip a part of the game you don't particularly like they are listed below.

Save File Links:
https://www.nexusmods.com/likeadragoninfinitewealth/mods/103/


Please rate and favourite if these guides have helped you! Awards are nice too but not necessary.

Save 1 is for the 30 Mins or It's Free achievement for completing all the crazy delivery courses. Just go in and finish the last one
Save 2 is for the Touching Lives achievement for completing 10 substories, just finish a substory on the map
Save 3 is for the Spirit of Aloha achievement for making 50 friends, just walk around for a while and say hey to people with an empty friend meter
Save 4 is for the Basking In Glory achievement for reaching a 4 star island on Dondoko, just talk to the shop owner and skip the dialogue
Save 5 is for the Dondoko Denouement achievement for finishing the Dondoko story, talk to the shopowner and finish the last fight
Save 6 is for the Saving Lives achievement, just head back to Hawaii and it'll show up, you also have $500k to spend however you want during chapter 6 of the game.
Save 7 is for the License to Skill achievement, just finish another test at the vocational school.
Save 8 is for the final exam in the vocational school
Save 9 is right in front of Alohappy for the Alo-Happy as Can Be achievement, just go on all the tours until you get the achievement
Save 10 is for the Investing In the Future achievement, just finish investing in Julie's store, you also have access to all available jobs except for Sujimancer in chapter 6
Save 11 is for the Precious Memories achievement for having seen 30 memoirs of a dragon, just go to the blue memory icons on the map, the ones to the right of you are easier than the one straight ahead.
Save 12 is for the Letting Go achievement for doing all of Tomizawa's drink links
Save 13 is for the Sujimaniac is for registering 100 sujimon to the sujidex, just go around and fight some sujimon, it might be easier to do it at raid spots or fighting king enemies on the street
Save 14 is for 2 achievements both Squared Away and Commanding Respect for finishing Nanba's and Seonhee's drink links
Save 15 Is for Abundant Memories for seeing 70 memoirs of a dragon, again just go to all the blue spots on the map.
Save 16 is for 3 achievements Missing Words and Starting fresh for finishing Saeko's and Zhao's drink links and then Side Hustle for getting to 30 in a job, just go to the dungeon or continue main story to get it there.
Save 17 is for the No Regrets achievement for finishing Adachi's drink links.
Save 18 is before the fight with Komaki, which is a very cool moment, no achievement but figured the save would be appreciated. If you also fight all the blue markers you can get the achievement
Also if you fight all the blue markers you can get the Sujimon Sensei achievement for registering 200 Sujimon
Save 19 is for the Ultimate Hustle achievement for reaching rank 30 in 7 jobs, just fight blue markers until you get it.
Save 20 is for the Renewed Purpose achievement for finishing all the life links, just go to the bar in front of you.
Save 21 is for the Living Your Best Life for finishing 40 substories go to blue marker at the art area.
Save 22 is for the Rest Assured achievement for finishing Chitose's drink links.
Save 23 is for the Prize Fighter achievement for maxing out a Sujimon, I have only done this with the DLC Kiryu Sujimon, so if you do not own this DLC you will have to grind for it yourself.
Save 24 is for the Suji League Champion achievement for finishing the Sujimon story, this is with the DLC fighters being at level 50, if you want to do this and dont own the DLC you will have to grind for a while.
Save 25 is for multiple achievements and is at the point of no return of Ichiban in the final chapter.
You can get Breaking Free for finishing Joongi's drink links, Pound for Pound for calling poundmates 30 times, just call them during any fight. If you continue the main story or do grinding in the dungeon you can get the Apex Dragon achievement for reaching level 50 as Ichiban and if you finish Ichiban's section you will get the achievement Funk Goes On for pushing Kiryu's soul to max
Save 26 is at the point of no return for Kiryu at the final chapter, you can use this to play the ending of the game
Save 27 is for Premium Adventure, you can use this file to play the Big Swell or do New Game Plus if you own the DLC, if not you can still just use it to mess around post game.

Legend and Hard NG+ saves listed in part 2

Bonus Saves:
Save 32 This one you will have to do straight away after moving the saves since it is in an autosave slot Save 32 is for the Dondoko A-Go-Go! for running a TV Ad on Dondoko, just talk to the kid on the beach.
Dont hate the player for meeting up with 5 matches in Miss Match, just do another successful date in Miss Match and you'll get this achievement, if you're struggling look up a guide.
Superhuman for raising one of Kasuga's personality stats to the max, just do anything that raises kindness and you will get this achievement.
Sicko Stopper for doing all the Sicko Snap courses, apparently the hard course is bugged for some so if you use the file here it has hard and easy finished and you just have to finish intermediate for the achievement.
Amon Ijincho is in the Ijincho dungeon right in front of the final boss, you can use this save to get the Dungeon Sweeper achievement,
It can be quite a tricky fight, you have access to all characters in this save but if you use my party I recommend using
Chitose and Saeko mainly to heal everyone else up, Kiryu and Seonhee are gonna be your main damage input, use tag teams,
Kiryu's real time attack mode, poundmates and good healing/mp items to your advantage, mainly just keep healing every turn
I also recommend focusing one Amon at a time and focusing on weaknesses, it's important to keep Kiryu's health up as
eventually the Jo Amon will resurrect everyone and do an attack that deals massive damage to Kiryu, if his health is too low
he will die. You could also equip the sacrifice stone on Kiryu just incase.
You can probably also use this save to get Somethin From Nothing, just craft a bunch of weapons at Julie's
Hawaii Robo Michio is in the Hawaiian Haunt right before the final boss, you can use this save to get the Ruffians Beware achievement,
This is a lot easier than the Amon fight, just cast Ichiban's Hero's Guts skill which will revive you if you end up getting an attack that would normally KO you.
Break It Up! Check the personality challenges in the menu and go to the third tab and look at the raids section, this unlocked the achievement for me.

Continued Below

For the first time ever I hit the maximum word limit in one of my guides, which is a first lol

Continued from above

Craftaholic for the achievement of the same name, craft an umbrella rack, yeah that's it lol. You can also get Island Hospitality for welcoming 100 guests to Dondoko Island, you will have to finish the current guests visit though, which will take around 20 minutes, just end the days as fast as you can.
Legendary Dragon, use the level booster in your inventory to get to level 70.
Metahuman and Infinite Wealth, use the style growth item and that will leave you with all maxed stats.

The remaining achievements all require the Big Swell and New Game Plus DLCs for the Big Swell saves, you'll be at about the right level for each floor.

Building Bonds and Making Gains is for clearing the first floor of the Big Swell, head to the beach, go through the cutscenes and then run through, rescue the people and defeat the boss, with your current level it's pretty easy.
Titillating Teamwork is for clearing the second floor of the big swell, head inside the dungeon and rush through all the floors.
Kei is for Kinship is for clearing the third floor of the big swell, you know the deal.
Unboxed Brotherhood for the fourth floor.
We Did It for the fifth and final floor.

Legend/Hard New Game Plus Finale Save
Listed as Finale Legend Hard and New Game Plus Final Save, you can use this to finish the game on legend for both Endless Vacation and We're Definitely the Best! achievements, just fight the final boss and skip all cutscenes, you can also use this to get We're Probably the Best! for beating the game on hard, for this go into settings and change the game difficulty to hard instead of legend.

After downloading the folder, unzip it using 7zip or winrar, inside is a folder called Infinite Wealth Saves open the folder and copy the files, this part is different from most the other Yakuza games so pay attention, you may need to make hidden folders/files appear in windows to find this folder, if you do not know how to do this, search on google for a guide.
To find the folder go to your taskbar and type in %appdata% a folder called roaming will appear, from there go to roaming\Sega\LikeADragon8\steam\ <user-id> \ and paste your saves there.

I really recommend backing up your own saves, just in case. You might need to turn off steam cloud for the game for this to work, to do that, right click on the in your library and go to properties and you will see a tickbox under steam cloud in general.

Enjoy, kyodais, I will see you again for the next RGG game, I also might do the kurohyou games saves, we'll see. Until next time, a hui hou and bonvoyage!